Can change their body at will.

I WAS CURIOUS COULD THIS HAVE BEEN REALLY STRONG BEFORE LIKE Mystique X-Men but then they did it too much and now they are mostly limited to like changing aspects of their own body. So their sex, their height, etc. They could still completely change to another person but are very leery of it and it takes both a lot of effort and they might get stuck so it's like nah bruh,,,,