Pretty easy achievement compared to the completionist one. (*not buggy :D)
*UPDATE: Some people have run into a glitch that may cause you to be unable to complete, (on your original save), this DLC. It is suggested that you complete all main missions before you do the side missions and other side activities. If this happens to you, a new save may fix this. See comments for more on this.
For the missions, you have to complete the objectives for your 100% sync in the level.
Mission 1:
*Kill 5 bluecoats while remaining undetected.
This one is pretty simple, the first 1 (other side of the graveyard) you can just walk up behind and stab. The second guy you want to run up behind and stab as soon as the roaming guard to the left is walking away from you. Then run into the bushes right by the tree you passed to kill the second guard. Stealth kill the roaming guard from the bushes. Now run up onto the roof of the church and jump into the hay cart down at the front doors. Kill the guard right next to it. Now whistle for the last guard and then kill the rest in open conflict.
*Prevent blucoats from reaching concord.
This one you need to use the cannon and shoot any troops that are advancing. Always aim slightly ahead of them as the shot takes a second to reach where you are aiming. If you fail, simply restart the checkpoint.
*Do not let a bluecoat light a fuse.
Basically all you need to do is run after the larger red blips on your map. They also have the blip over their head when they appear. At first there will be one at a time and then two at a time. They take the same paths (2 different paths) so if you fail the first time, restart the checkpoint and head them off where you know they're going.
Mission 2:
*no objective
Mission 3:
*Don't touch any rocks during slides.
This one is rather simple. You will get to a point in the mission where you slide down a slight hill and rocks will become visible as you're falling. Simply maneuver through them and avoid landing on the big rock at the bottom (*first slide does not affect this as you have to land on it*)
*kill the elk without alerting it.
With your new power, simply activate it and slowly walk up behind the elk and kill it.
Mission 4:
*Kill 2 bluecoats with a single arrow.
After you analyze the four clues and watch a cutscene, you'll be given a waypoint and ahead of you 2 soldiers are running up the hill. Simply run to catch up and line up a shot right behind both of them. The arrow will go through and kill both of them. Note: You just have to hold the button down until the arrow in the bow is fully drawn back. (hold Y for about 4 seconds)
*Kill the runner by calling the wolf pack.
This is when you just received your ability within an ability. Simply press LB when chasing the runner and let the wolves kill him.
Mission 5:
*Use no stalking bushes during the eavesdrop.
I found sneaking over on the left side to the barn at the beginning made things a little easier. Activate your wolf power and jump into the hay cart at the beginning of the eavesdrop. Once the 2 guys are moving press the Y button to exit the hiding spot and automatically go into your ability mode. Follow close behind and then hide in the well to get your health back. Once the horse guard and the 2 guys start moving again press Y yet again and follow to the final area after the eavesdrop finishes.
Mission 6:
*Free the bear without alerting (and without killing) the guards.
Simply work your way to the bushes nearby with your power. Make sure you are full health and then activate it and move to the front of the cages. Hold down the B button to slowly unlock the cage. Then quickly move to the bushes behind the cages.
*Stay undetected in the fort.
This should be pretty easy now that you've gotten used to your power. Simply stick to the bushes and work your way up the hill. Then once you find your target, kill it. Best to equip your hidden blade first just in case.
That will give you 100% for the missions. Now for the side events.
****Note: All of these side quests are easily completed when you are first introduced to the frontier and you have a bunch of treasure chests to obtain.****
*Note: Treasure chests are not required for this achievement. So you can choose whether or not to obtain them or not. -Credit for this goes to Lechig.- (Thanks!)*
I found the side missions to be best gathered while gathering all the treasure chests. The reason is, you will run into most if not all of your convoys along the way. This will save you a lot of time instead of just wandering around looking for them.
Treasure Chests (not needed*):
These are simple enough. Simply look at the map, set a marker and head there. There will be a lot of fights as 90% are guarded. Also if you do go for these, there is one chest that is unobtainable until mission 6. It's inside a fort with the cages in the front. (upper left side of the map). During mission 6 you can gather this one pretty early on.
Convoys:
Most are found while gathering your treasure chests. If you are still missing some, these activities do respawn in the same spots. So if you see one along the way, remember the location so you can head there a later time and not have to worry about it.
Help the Hungry:
This is the easiest of the side missions. The barracks on the left side of the map has 5 in there alone. You'll run across quite a few if you go for the treasure chests.
Wolf Rescue:
This one I found harder to find people to save. There is a spot in between the towns in the middle of the map where you can do this. Simply rescue the guy, then walk to the town on the right side of the map. Then walk back and you should be able to rescue him again.
Memory Artifacts:
If you are going for the treasure chests, these will eventually appear near you on the map. The First one is given to you on the map already when you first enter the frontier. The second is in the middle of the barracks on the left side of the map. Finally, the last is located in the top middle near the river next to "your" village that has burned down. (After collecting all three there is a little bonus interaction for you to do :D)
*****If there is anything missing or anything that would be more helpful to those going for this please state it in the comments. I'll credit you and add it in it's corresponding place. Hope this helps those that are a little stuck, and happy cheevo hunting!*****