Raven
I think it's because you can shapeshift that would make this wicked sweet. Keep me on my toes if we did one where you shifted mid-fight.
I have a feeling you might be one of my favorite sparring partners ever. It's important to me to make sure I'm still capable without using my powers, and in this place, you never know when you might lose them.
I won't tell them, of course. But it's not like they don't know we wouldn't skin them alive if they tried to watch.