I just obtained this achievement a couple of days ago, and since it's still fresh in my head I felt I should share my experience with everyone who is going for this, and especially the people who are struggling with it. This is basically a text walkthrough in case people are having trouble with the video walkthroughs, and also I've found shortcuts through certain levels that aren't in the videos. First off, you'll need the Plasma Rifle for this difficulty level. This is absolutely essential as it's a 1 to 2 hit kill on all enemies except bosses. You can obtain this by going through the game on Agent difficulty and picking it up on mission 12, or you can ask a friend who already has the gun to drop it on the ground for you in Coop. Just make sure you finish the level with the weapon. Also try to get the Hawk for Mission 3 (can be picked up on Mission 9 Jungle), and the Viblade for Mission 13 (found in Mission 4 Mansion Infiltration). Now onto each Mission.
This is the tutorial mission, and the ONLY mission in the game with a checkpoint on this difficulty. This mission is pretty straightforward until you get to the elevator. Spiderbots will start attacking from the wall and door. Make sure you quickly pick up the Laptop gun behind you and use it's secondary function using RB. Make sure you throw the turret on the wall where the Spiderbots are coming from and then pick up your Plasma Rifle again. This way you'll only have to worry about the Spiderbots coming from the door and not the wall. When you get to the top you'll want to take it slow outside. Use your invisibility (RB on Plasma) and slowly pick off the enemies from the left side and then the right. Watch out for the ship shooting at you as it will tear you apart. When you get on the next elevator you'll be attacked by 3-4 Jetpack enemies. Make sure to roll whenever one of them begins shooting at you otherwise you'll take massive damage. Use your invisibility wisely. When you get to the top either use the invisibility if it's full or push up on the D-Pad and run as fast as you can to the door in front of you on the right, and roll if you are getting shot at.
This mission is all about stealth. Make sure you have your P9P. If you start running and gunning, you'll either fail the mission or get shredded by the enemies in the nightclub. You have to scan three lieutenants before entering the Nightclub (Right on the D-Pad). There will be one directly up the stairs in the beginning, another farther to the right where a Speedboat is docked, and the third can be accessed by a lift behind a wall you blow up. Kill all enemies outside with your Sniper weapon unless you get rushed, then it's Plasma and Invisibility time. Go through the Nightclub from below, taking out the 3 enemies down there. Go up the stairs and through the hallway to the end, where one enemy will be sitting at a desk. Kill him and sound the alarm to get the civilians out (if you mistakenly shoot one then the mission fails and you have to start over). Open the door and take out the enemy standing by the mid-stairs. This will trigger 3 other enemies coming after you 1 by 1. Kill them with the Plasma and then slowly take out the Bartender on the right, then the left. Now all the enemies will be upstairs, use Invisibility to make it to the mid-stairs and take cover. Most of the time the enemies will be on the other side, but occasionally they'll try and flank you from the sides, if so then roll, go Invisible and then take them out with the Plasma. Kill the enemies from the other side with your Sniper gun. When you get to the next area take it slow, as there are a TON of enemies. Use Invisibility to take out at least 2 of them and then roll back out of their firing range. Wait for them to run 1 by 1 to you so you can easily take them out. Be careful with the Bartender behind the bar, as he can take off alot of your health with his Uzis. The next area has about 4-5 guys that you can slowly take out by luring them through the door, where you can blast them away. Watch out for the Bartender below. They'll be 2 enemies in the next room. Go invisible to see where they're located and then take them out. Wait in the room for a minute as 2-3 enemies will spawn from either upstairs or downstairs and rush into the room. The next set of stairs leads to the turrets and then end of the level. Take it VERY SLOW. Use Invisibility to see where the first turret is located and then quickly go back down the stairs. Use it again to target and destroy it. There will be two more turrets all the way on the left and all the way on the right. Take out the one on the left first using the Invisibility trick, and then the one on the right. Walk slowly down the hall and use Invisibility to quickly peak down the other hall at the end. There will be two turrets randomly spawned on the walls. Kill the first one, let your Cloak recharge, and then kill the second. End of Mission.
This mission starts you right out in the action, but all you really have to do is use your Cloak, run to cover, and take out the bikers one by one. Grab the keycard and exit the garage. Take out the cameras otherwise they'll alert about half a dozen enemies. Use your Locktopus and kill the 2 enemies upstairs. Use Invisibility and kill the enemy in the next room. Kill the 2-3 enemies downstairs and then kill all the enemies upstairs using cover by the door on the left. Blow up the building and go outside. Kill the one enemy patrolling the area, and then wait for the next one to run around the corner and then blast him away. Peek your head out and kill the enemy on the second floor to the right and then on the first floor on the right. Go inside the building and go all the way to the back while invisible to kill the enemy hiding on the side. Go upstairs, find the access code in the filing cabinets, and go pick up the suitcase. Now go to the subway. Take out one enemy at a time while using wall cover until you reach the area with both bikers and agents. Kill one biker without being seen to start a gunfight between the 2. Wait for the carnage to end and then slowly make your way down there, taking out whoever survived. Once you see the train, go down the stairs and kill the guy on the left, then run behind the cover on the right. Take out the 2-3 guys who are shooting directly in front of you. Use your P9P to scope out farther down the train. If you see an enemy, try to get a headshot. If not they'll run to the front of the train where you can take them out from cover with your Plasma. Go in the train, crouch (push in the left Analog stick) and slowly make your way to the end, killing whoever is waiting for you on the train. When you get out immediately Cloak and run to the wall on the right. Directly above you they'll be 3-4 agents, use wall cover and take them out one at a time. There will usually be 2-3 agents waiting for you inside the door ahead, so go invisible, kill one then run/roll outside and repeat the process until they're all dead. Carefully go up the stairs and make sure each enemy is dead. Run down the stairs and through the door on the side. End of level.
Make sure you have the Hawk equipped for the boss fight at the end of this level. Make sure to take out the snipers before they kill Jack otherwise you fail the mission and have to start over. Once you take out the first batch of enemies, go to wall cover and take out each agent one by one. Go into the pipe and take out the enemy through the glass below, then quickly turn around and kill the enemy that spawns behind you. Drop down into the next building and kill the enemy in front of you, go invisible then kill the Sniper outside on the left. Wait for Jack to hit the alarm and then go Invisible and go through the walkway in the middle. Go outside and Protect Jack from the enemies in the building below straight ahead, your Plasma will make short work of them. Use the Zipline to activate the switch, then use another Zipline and hide behind cover while Killian shoots at nothing for a few minutes. Go forward and hack the device below (kill the agent if he spawns here). Go slowly up the stairs and use your invisibility to scope out the enemies above. Kill the 1 enemy in front, and then use wall cover to kill the next 2. Go Invisible and peak over the ledge to see how many enemies are below and take out one if you can, then roll backward. Repeat this process with the other two. Jump down, and kill the enemy through the window below if he spawned there. Now it's time to fight the boss. Immediately go behind the shed and start blasting one of his engines if you can. This will cause it to start smoking which will make it easier for you to follow his movements. Once you've done enough damage to him, he'll start firing rockets at you, make sure to take out your Hawk and use RB to shield yourself from damage. Use this and always make sure he's in front of you and the tip of the shed is above you. If you see an opening to shoot his engine while he's firing at you with just bullets, then do it. When he goes to drop off soliders make sure you shoot the middle of his ship first to kill as many enemies as you can, and then try to shoot his engine at least 4-5 times before he goes back into the air. Repeat this process until his ship blows up. Makre sure to NOT get killed by his soliders right after otherwise you fail the mission (there's like a 10-20 second window from when you kill him and the mission ends). End of Level.
Ah, the Mansion level, how I hated this one. Stealth is the name of the game again in this level. Always snipe the snipers first, from left to right (there are 4 total), then try to sniper the 3 guards randoly walking around, while avoiding the others. If one sees you you have about a 5 second window to kill him before he calls in reinforcements. Once they're dead, pick up the radio and make sure to listen to what the guy says. If he talks about Lee or Maintenance, then you choose Bluff. If he talks in a friendly manner or is concerned for your well being, then it's Charm. And if he sounds pissed off, or frightened then use Threaten. If you put in the wrong answer then he'll send about 5-6 soldiers after you and it'll pretty much mean instant death. Go to the left up the stairs and then slowly go up the next stairs and use your invisibility to scope out the area. If there's a guard behind you then let him walk back where the others are. Now go behind cover on the left and blast all the enemies in front of you and below to the left. I highly suggest you take them out one at a time and go back behind cover until they start to reload, then kill another one. Sometimes the enemies from the middle of the bottom stairs won't run up right away so be weary of that. When they're all dead make sure to active the satellite up there before heading to the door. Before using the intercom, shoot out the camera above you to your left. Now use the same dialogue process from before to get inside. Once inside, run over to the left and up the stairs. Take the camera out in front of you and then scan the woman over to the right. Once the scan is completed, go left through the building, and take out the 3 cameras with your P9P. Before you go through the door make sure you're unarmed otherwise the guard will run off and call reinforcements. Run past him and down the stairs and go right, punch your way through the glass and go up to the guy and activate Charm to get inside. Now you fight Mei Hem. This fight is annoying, and will probably take you a few tries and a little luck. When you spawn, immediately go behind cover and shoot the hell out of her with your Magnum. If you activated the satellite before, you'll get a choice of 1 of 3 extra weapons. I always choose the shield as it makes killing the statues easy. When a statue runs up to you, all you have to do is hold down LT and melee it with B. You won't take any damage from it, even if there's three surrounding you. Always make sure you roll as soon as you hear Mei Hem or any of her clones start shooting, as 90% of the time you will avoid their fire, even if they spawn right next to you. Once you start killing her clones, they'll drop a Superdragon. Make sure you pick this up, and start killing all the clones with it's rockets. When all the clones are dead, more statues will go after you, kill all but 1, then run around and pick up some ammo. Go to the top of the right side of the stairs and kill the 1 remaining statue. Mai Hem should spawn right below you. Immediately shoot as many rockets as you can at her. Killing her will end the mission, killing the statues first will enable her to kill you and then you'll have to start this hell all over again.
This is a very simple mission if you follow the way I did it. As soon as you spawn, go out and snipe the guard walking around. Make sure he's far enough away from the other guards otherwise they'll push the alarm and call for about 20 female guards (I'm not joking). Now snipe the 3 stationary guards by each of the doors. Go through the door over to the right in the middle. There will be a guard standing there, kill him before he can warn the others downstairs. Go down and kill the enemies down there, starting with being invisible and then shooting the barrels so they explode and kill the rest. The gas will now be turned on. Go farther down and quickly kill the two enemies near the switch. DON'T turn off the switch. Go to the vent and melee it to get through. Run through the tunnel and go through the next vent. Go over to the guy with the Fishbowl on his head and point your gun to him. He'll go turn off the gas. Grab the keycard on the table and go through the door above. Now use the Keycard to get through the locked door. Go invisible right before going in there, and then quickly go grab the keycard on the table to the left, then quickly leave before the scientist spots you and sounds the alarm. Now go through the open walkway that was on your left at the beginning of the game. Go invisible before you get to the bottom, and then kill the guard down there. Use the keycard to open the locked door. Now go to wall cover behind the crate in front of you and take out every enemy you can in front of you. When they're all dead, go to the left and take the elevator up. Go Invisible again to see how many enemies are at the top and take them out one at a time. Only when you're absolutely sure they're all dead, go to the middle and up the stairs. Before you reach the top, go invisible and kill the guard. Now check to see which cell Jack is in from the left monitor and open it using the right monitor. Run over and go invisible before opening the door and scope out where the enemies are. Take out only 1 or 2 and then run back and go to wall cover. Enemies will start running out after you one at a time so take them out accordingly. Sometimes they'll stop and you'll have to run in there again and get their attention. Just do the same thing, go invisible and kill 1 and then run back out. When they're all dead you can run to Jack in his random cell you opened and the level will be over.
As soon as this mission starts run up the stairs and get on the turret. Kill all the enemies that come through the door. Now slowly make your way outside the door while invisible and hide behind the boxes. Now take out all the enemies in front of you one at a time. Try to snipe the two enemies all the way on the other side behind the bridge. Go to the left bridge and shoot it until it raises. Now go to the right bridge and shoot it until it drops. As soon as you cross the bridge enemies will starts running through the door. Destroy them as fast as you can with your Plasma gun. Now you have to protect Jack while he blows up the wall to the right. Two enemies will always come from the left side and another two will always come from all the way on the other side of the hall, so be ready to snipe/Plasma them. Once the wall blows open, about 6-7 enemies will try to rush inside and annihilate you. Try to kill each one that comes in and if one makes it in, then roll, go invisible, then shoot. Now go to wall cover and take out everyone you can see, especially the guys on the turrets. If the enemy is far enough away from you and on a turret then they won't move no matter how many times you shoot them. Make sure to kill the guy on the turret directly to the right of you. Now line your Plasma gun up perfectly with the two guards in the huts to the right and kill them. The sniper won't kill them and their extremely fast and dangerous, so many sure you're using the Plasma and it'll be dead center. Go to the right under the walkway and kill the enemies directly to your left. Now go left and up the stairs very slowly. They'll be a guy on the right in a corner hiding. Try to snipe him as soon as you see him, he's always on the ground floor near a wall. Once all the enemies are killed outside then continue down the stairs. Go activate the switch to open the doors. They'll be two female guards in one of the small buildings to the right of your hovercraft. Go invisible and kill them one at a time. Be careful because their gun can cause you massive damage. Now destroy all those Hovercrafts that they were protecting. Run over to the turret with the rocket launcher and switch it with your Plasma Rifle. Now go to your Hovercraft and equip the Rockets at the top. Get in the Hovercraft and get out of there as fast as you can as multiple enemies spawn. Now have Jack take out all the equipment and enemies with the rockets. If your boat starts taking damage and the screen starts turning red, then hide behind a rock for a few seconds until it goes away. Keep going to the yellow targets on your map so Jack and destroy them, and watch out for the occasional Hovercraft that will drive in to attack you. Once all the yellow targets are destroyed you're told to destroy one more Hovercraft, drive to it and let Jack annihilate it with the rockets. Level over.
Immediately go to the wall on your left and go to wall cover. Always shoot the fat bounty hunter on the right first. Make sure you never fire at him any more than two times otherwise he'll start shooting back and damage you immensely. Be weary that the bounty hunters sometimes like to throw turrets on the sides of walls right before they die. Once the fat one is dead, turn your attention to the skinny one. Use the same method of shooting him no more than twice before going back to cover. When they die be cautious of those turrets. Now start opening the containers to the left and right of you. One of them contains X-Ray glasses. Use these by pushing right on the D-Pad. Usually they'll be 3 enemies over to the left that come out the door and start patrolling the area. Just use the glasses and take them out with your Plasma. Don't go up the stairs, instead, head slightly to the rocket. There will be 3 snipers randomly spawned on either side of the buildings. Use the glasses to spot them directly. Now take out your P9P. Line up your shot perfectly. Now take out your Plasma and fire off no more than 4 shots. Go behind cover just in case you missed. Use your glasses to see if the sniper is dead. Now repeat this process with the other two snipers. When all 3 are dead, go to the left of the rocket until you reach the building. There will be a crack in the wall, blow it up and go inside and active the elevator. When you get to the bottom there will be guards at the left and right doors. Go invisible and go out and kill one, then roll back into the elevator. The guards will usually stop right where they are, and if they start shooting, they'll shoot the glass which is bulletproof. Kill the 2 remaining and go left, then go up that elevator. Again, they'll be more guards on both sides. Use the same tactic and kill them all systematically. When they're all dead go right. You'll see over a dozen guards downstairs being yelled at by their drill instructor. Ignore them and continue right upstairs and kill the guard patrolling. Now keep going right until you see a guard patrolling the left side, kill him and look on the desk. Activate it to page the Doctor. Before you follow the blue arrow, go into the hallway straight ahead and kill the 2-3 guards patrolling. Remember all those guards downstairs, well they're now coming after you. Go a little farther through the hallway and you should see the wall to your left where you can take cover. Do so. Now watch as the dumbass AI comes after you one at a time and destroy them with your Plasma Rifle. Once they're all dead, now you can start following the blue arrow. You'll eventually go into a room with a bunch of cameras. Just destroy the three on the bottom floor, don't worry about any on the second floor. Make sure you have your glasses activated and keep following the arrow till you run into the Doc. Sometimes you'll have to kill 3 enemies before you reach the end and sometimes you don't. Just make sure those glasses are activated so you'll know ahead of time. Level over.
In this mission you start off with 3 extra guys protecting you. Sounds awesome right? Sure, until one of them stupidly runs into your Plasma fire and causes you to fail the mission. Just be aware of that, and shoot wisely. You immediately start off seeing guards with shields ahead of you, kill them and any that are behind them. Let Jonathon hack the device and always aim your gun at the door. Sometimes and enemy will try to run through and sometimes they won't. Now go down the walkway and go in the door straight ahead, not to the right. Go invisible and take out as many enemies as you can (I believe there are 6 total in here). When they're all taken care of, go through the door ahead and the Demolition guy will start setting charges to close the door. Directly ahead of you about 6-7 enemies will start flooding out the door trying to shoot him, just blast them away with your Plasma. The next area wants you to use your Locktopus, but before you do that go to wall cover and take out the 4 enemies down the hallway. Once you're done with the Locktopus, keep going and you go into an open area. Most of the soliders will be running from the other side of the room straight to you, and there will be a few over to the right side. Concentrate on the ones ahead, as your team AI does a pretty good job of killing all the enemies to the right. Once they're all dead, keep moving forward till you reach another area where the demo guy sets up. While he sets up, keep your gun slightly to the left of him as sometimes enemies will spawn and try to attack him. Once that door closes move forward and go invisible and go through the right door, killing the 3 enemies inside. Let your Cloak recharge and active invisibility again and kill the two guards through the door ahead, and then kill the one over to the left. Now go to the door on the other side and see if the AI killed all those guards and if not, finish them off. Go downstairs and go through the door on the right and kill the two guards with the shields. Now go through another right door and kill the two guards hiding behind the wall. You are now running through the same level as in the tutorial. Run to the door on the other side and all the way down the hall until the Demolition guy is ready to set up again (assuming he's even still alive). Protect him just in case enemies spawn from the other side of the hall. Now you'll run through one of the most annoying parts of the level, as soon as you go through the door, they'll be an enemy directly to your right, kill him then immediately try to kill the two to your left. Now enemies will be randomly shooting you from downstairs, so try to find cover and take them out one at a time. The demo guy might die here, but he isn't necessary to finish the level. Try to keep the shotgun guy alive though, as he helps out greatly when you reach the top. Just go very slowly to the bottom, checking over the railing every chance you get. Once you kill all the enemies, then it's time to ride the elevator to the top. If all three of your AI teammates are alive, consider yourself very lucky. When you open the door to the top, you basically have a limited amount of time to clear out the enemies before they destroy the ship and you have to go through this aggravation again. Immediately take out the guy on the turret to the left, then get to cover and try to Snipe/Plasma and many enemies as you can. Your AI teammate with the shotgun will help you greatly here, assuming he's still alive. The demo guy will most certainly die. Once it says the ship is safe you're not timed anymore, but you still have to be careful because there's enemies both to the left and right. Take them out if they're in your way and get to the ship to end the level.
This is basically the hardest mission in the game. You'll immediately be thrown into a firefight with about 50 enemies and almost nowhere to find cover. You have to kill them all before they destroy the ship you just got off of. You also have to do this while most of them are almost impossible to see because of the trees. Immediately run to your left and take cover behind the boxes. Take out as many enemies as you can before they destroy the box. Move to the other box when it gets destroyed. When they destroy that, go to the rock on your left and take cover behind that. Also, be VERY VERY aware of grenades. They will be thrown at you frequently, and if you stick around too long, it will inflict massive damage on you. Once you get through that hell, go to your AI teammate by the ship and he'll give you heat sensing glasses, which is essential on this level. Now go forward and to your left. The Scottish guy on the radio will tell you about the Spiderbots ahead. Take them out with your Plasma gun along with the guard next to it. Now here comes aggravating part #2. There are enemies everywhere ahead, in each of the huts, on top of the huts, and a few outside patrolling. What you want to do is go invisible, crouch near the rock and let your Cloak recharge, and then go invisible again and run into the MIDDLE hut. Make sure to kill the enemy in there immediately. Now stay there for a second and let the cloak recharge again. Try to go forward a little before activating your invisibility but if you see an enemy immediately activate it and try to make it to the hut above and slightly to the left. Kill the enemy in there as soon as you see him and then take cover behind the crates. The enemies will most likely run looking for you, but then run away about a minute later. Go invisible, take cover on the left wall, and try to kill the enemy standing on top of the Hut. Now go to the ladder, activate your invisibility and climb up it, then immediately kill the solider there. Let Cloak recharge, go invisible again and go to the next Hut and kill the solider in there. Go to wall cover, and kill the enemy on the top of the hut. Now you should be clear to get to the next part. Move forward and down and activate your heat sensing glasses. There should be three enemies here, and one will be hiding behind the statue. Kill them one at a time and always remember to roll away when they start shooting. When they're dead, move forward until you see a pathway. Slowly take the left and use the glasses till you see enemies. There should be three, one at the bottom, one inside the waterfall ahead, and the last one will be at the top. Again kill them one at a time, watching out for grenades they might lob at you. When all three of them are dead, go back the way you came and go to the right side of the split, go invisible and kill the one enemy there, then try to kill the other enemy all the way on the other side. Sometimes you can get lucky and your Plasma bolts will kill him and sometimes he avoids them. Now take it real slow, use the glasses, and use your invisibility wisely, as these enemies can kill you almost instantly if they spot you. Once they're all finally dead, you can move on to the next area. Run forward and you'll see about 4-5 enemies attacking someone the Scottish guy told you to rescue. From this vantage point you can snipe all of them as long as they don't run behind the rock. There might be one left alive that you'll have to deal with afterward. Once they're all dead, go forward and you'll see a destroyed ship. If you move a little farther a ton of enemies will start spawning, but they won't attack you until you fire at them. Run as far back as you can, and try to snipe one of them. Now run back behind the wall and the idiots will start coming after you one by one, to which you can blast them with the Plasma. Do this until they're all dead. If the Doc is still alive, then you don't have to worry about that extra solider. If he's dead, then go hunt that other guy down so he doesn't screw you over. Make sure you have your glasses on again, cause now you have to shoot mines. The Plasma Rifle won't work, so you have to use your P9P or one of the guns that the enemies dropped. Watch out for Spiderbots as well, they will do massive damage. There's a Spiderbot sensor to the right of the Temple and another one behind it. Once you destroy both and all the mines in your way, you get to the bridge, which is destroyed. There's a Jetpack there that you need to ride, but first you need to kill the enemies to get to it. I believe there's 4-5 soliders here and another two on Jetpacks on the other side of the bridge. Go invisible and shoot one of the soliders to get their attention, then run behind cover and wait for them to come after you one at a time. Take them out and then peak your head out to see where the Jetpack guys are located. Go invisible and try to shoot one down, then roll back into cover immediately, as these guys can kill you instantly. Try to kill the other one doing the same thing and when they're both dead you should finally be able to pick up the the Jetpack. Now make sure you fly high into the air (LT) to avoid the enemies below shooting you to shit. Fly over the bridge and past the trees and then lower down at the entrance to the temple on the right. Push RB and then A to get out of the damn thing and roll your way into the next level.
There's really not much advice I can give on the first part of the level. You basically need to get to the end as quick as possible and everytime you have to start over enemies spawn randomly somewhere else. A few pointers I can give are memorize the level and where you need to get to as soon as possible, when walking over collapsible wood, go invisible with your Plasma Rifle and it will prevent you from falling through, and sometimes, when you get to the scientist you have to save, if you crouch first and then use your Locktopus, enemies won't shoot you, but sometimes they will. Once you rescue the scientist, you'll have to kill all the enemies in the area with the water ahead. Going into the water will disable your invisibility, so you'll have to roll your ass off to avoid getting shot. Sometimes these soldiers throw turrets on the wall which basically means your screwed unless you get lucky and kill it immediately. Once all the enemies are dead, the scientist will finally move forward, which basically wastes more of your limited time on this level. There's an enemy right outside the door, so watch out for him, and it's sometimes it's worse cause there could be a turret as well. Go to the door on the right and watch the scientist take his sweetass time opening the door for you. Now go through the little jungle area and be aware of the three enemies out here. Once you get past them you have to melee 2 boxes onto the pressure points to raise the bridge, then you have to activate your camspy and drive it to the lift in the middle. Once that's done, you get to what I guess is another boss fight. Only now you're being attacked by about 10 soldiers with the Plasma Rifle that are invisible. How I did this was I went to the wall BEHIND where I spawned and waited for them to come to me. I blasted the hell out of them and kept going back behind the wall when the shot at me. I did NOT use the wall cover though, they will overrun and kill you that way. Once the last solider dies, the level ends.
This level is extremely difficult. You basically have to watch your back at every turn. One thing though is that Jonathon can't die, so let him take the brunt of the damage while you try to take out enemies one at a time. You start out having to rescue them, so before you use the Zipline to get down there, take out as many enemies as you can. I believe there are three guarding them, 2-3 to the right, and 4 down at the bottom. Once they're all dead you move forward and are told to take out a bunch of enemies running under the bridge you're on. Do so if you want, but I don't remember them causing any problems if you fail that objective. Just make sure you kill all the dropships you see. Shoot them from as far away as possible and watch out for enemies flanking you from both sides. Keep progressing forward and watch out for enemies in buildings who could deal massive damage to you. Basically you have to get lucky to get to the boss fight without almost all your health gone. Once you reach the arena, Mai Hem is sitting on a turret on top of a Hovercraft. Immediately, and I mean IMMEDIATELY kill the driver. If you did so, Mai Hem is a piece of cake, if not you'll be rolling all over the place trying to avoid turret fire. Also, make sure not to kill your allies, who are running around in the backround on the walkway supposedly trying to help you. Once you kill her, go to the window and blow up the last dropship, and it's mission over.
Now there's two ways to do this mission. You can run past EVERYTHING in the whole level, get lucky, and make it to the end. Or you can kill every damn thing in the level. After trying option 1 about 20 times and failing, I said screw it and killed ALL enemies. You spawn on a turret and unless you get off it in 5 seconds, 2 Jetpack guys will annihilate you. So jump off it, go invisible, and blow them to hell. Now you run into teammate AI fighting off half a dozen snipers and about 10 soldiers. Run over to the right side, take cover behind the wall, and start taking out the Snipers one by one with your Plasma. Watch out for your idiotic teammates, who like to run directly in your line of fire sometimes. When they're all dead, go into the Temple with Jonathon and take out the guys with shields. There's usually 3 shield guys at the bottom, and I believe you run into another 3 on your way to the top. When your where the top of the statue is, don't go up the stairs yet, as there are 3 enemies just waiting for you. Go invisible, and take them out 1 by 1. Jonathon is actually pretty helpful here, as his gun will instantly kill all enemies. Go up the stairs, but don't go outside just yet, go right and go invisible right near the end of the wall, there's two enemies on the other side, and one with a Rocket Launcher, which can kill Jonathon instantly. Kill them, and go back down the stairs and out the Temple.You need to go all the way to the door on the left side. And when you get there, you need to wait forever for the idiot Jonathon to open it. Once he finally does, you'll be told to storm the bridge, and you'll see about 100 enemies outside. Try to kill the 2 guys on Jetpacks to the right with your Plasma real fast, as they don't move right away, then go to the left and pick up a Jackel real quick and snipe as many enemies as possible. When it looks clear enough, go outside and you'll be told to take out Spiderbots before they take down the bridge. Do so immediately, but don't run across the bridge just yet. Go forward a little to spawn SOME of the enemies, then run back to safety and behind the wall if you can. Then take them out with your Plasma or any other gun lying around that can help you. When their all dead, you can finally run across the bridge. Once it says objective complete though, run your ass right back behind cover. Now about 50 more enemies will spawn. What I did was I ran back inside the fort and went to wall cover on the left. From there you can sometimes shoot the enemies from far away, and they can't hit you at that moment. But eventually they'll make it to where you are. Again though, these idiots will run inside one at a time where you can easily pick them off from wall cover. Do this until they are ALL DEAD. Wait a couple extra minutes if you have to to make sure there are none left. Now run forward across the bridge and when you get to the end run up the stairs and go right. If you're fast enough, you can avoid the cloaked women entirely, but if not at least one will appear and try to take a shot at you. As soon as you see one, go invisible immediately and just go past her. When far enough away go back to running and soon enough you'll see the end of the level.
Finally, the last mission. In this one you have to fight Zhang Li and his twin. make sure you have the Viblade on you. Only concentrate on one until you've killed him, then destroy the other. When you start shooting your plasma at him he'll deflect the bullets back at you sometimes so be prepared to roll alot. The best time to damage him is when he goes to pick up a statue, you can really shoot the hell out of him then. Just roll away from it when he throws it at you. Eventually he'll jump in the circle to take a swipe at you with his Viblade, try to get the timing right when he swipes at you to avoid a bunch of damage. Then take your Viblade out and cut into him like hell. Sometimes he'll die right there, other times he'll jump away and have to be shot some more. Just watch out for his twin because he likes shooting Plasma bolts are you as soon as your back is turned to him. Once you kill both, you have to wait a few minutes for some stupid reason. Then you finally get the cutscene and the glorious achievement will unlock LOL.
I hope this walkthrough will help some people who are still having problems with this game. This is all coming from my personal experience with the game. I played some of these levels so many times that these were the best ways for me to get through it. Good luck to everyone, and even though it's an extremely hard game, the achievement is truly rewarding when it finally unlocks for you.