This cheevo will pop when you complete the mission THE HIDDEN ENEMY.
Asaji Ventress 1/6
When the mission start use the jedi marker and then the force to cut through the glass window.
Use the clone trooper on the grapple point and switch back to anakin and jump on the lift which will carry him across.
Press X and the use the force to break through the window.
Use the force to close the red path door.
On the left pull the plug out and plug it into the socket next to the door in order to proceed through that door.
Use the force to close the left hand red path door.
Pull the plug out of the connon and use the force on it to block the right hand door. Enter the lift.
Stand on the red switch to close the door behind you and stop the enemy spawning.
Go to the right and same again, red switch, close door, enemy no spawn.
Kill all enemies and build the blocks in the center. The door will open again so shut both door and kill all enemies again.
Jump on the connon and blow up the 2 shiney silver enemy cannons and allow you gunship to land.
Those pesky doors are open again. close them.
One of those droids you keep fighting will lose his head. find him, cut his head off and wear it as a hat. Activate the droid panel on the gunship to escape.
In this room the blue wing shaps have to be moved using the force to the purple equivilents.
Go through the open door.
Fight Ventress. Jump and press X to knock her saber out of her hand.
Now u have 2 sabers, go attack her.
She will lose 1 heart and stael her saber back.
Repeat untill all 4 hearts are gone.
Once thats done she gets 3 hearts back and starts to throw stuff at you. Force grab it throw it back.
Repeat untill all 3 hearts are gone.
Stage 3 is the same as stage 2 but she moves to the upper left platform. Do the same as stage 2.
Once her health is gone she moves to the right hand platform.
Repeat as before.
Once Ventress makes her escape use the jedi marker and cut your way through the door.
In the next room avoid the book Ventress throws at you (guess readin is hazardous to your health) and use the jump and X method as described before to remove all 3 hearts.
Once you defeat her follow her through the door and as you get close to her she will collapse the floor.
Catch the steps she throws at you and place the on the wall and again she retreats.
ventress will climb inside a huge spider droid. Throw your saber at each gun as it turns.
Once it shows a foot saber throw it and she will stamp a few times and eventually get her foot stuck. Use the jedi marker that appears and cut it's leg off.
Repeat for the other side.
Eventually you will jump onto the droids head and fight Ventress again.
She will throw things at you so grab themn and throw them back to get rid of the silver hearts.
Jump down and saber attack her.
Rinse and repeat untill she is defeated.
Cutscene and mission end.