some people are confused on how she works, so here's what i found out

Sync makes both you and your clone move at the same time, while Feign moves your clone and not you, allowing you to Feign that you switched control (or set your clone up)

swapping takes atleast 2-3 frames, during this time you wont perform a move, if you are about to be attacked, if its within that tiny window, blocking is 100% better than swapping because you WILL NOT SWAP if hit, leaving you defenseless.

pretty sure your killer movement options ( there are 2 per stance, killer stride, step, and leap is on both) make both you AND your clone stalk at the same time, even if Feign is toggled. i need to test more to ensure however.-
it only puts into stalk the one that is being effected, meaning that you can make your clone invisible and not you, should you want to. pretty neat!

that said, you and your clone can have separate stances at the same time, dunno if its intended that way, but it certainly seems to function that way

Killer Leap is directional to your opponent, meaning if you sync a Killer Leap your clone will not go in the same direction as you, but rather in the direction you would jump if you were in the clone's place, relative to your opponent. think same side, same jump, opposite sides, flipped jump.

leave other things you discover down below and i will update this page as new info is brought in.
Happy hunting!