Who should be the third Overwatch Character?

I have the sudden urge to animate my favorite buff gals from Overwatch and the pose I'm gonna use as reference is something you've no doubt seen before:

Disclaimer: Art is not mine. All credit goes to: nikcesco.

Problem is: I can't make up my mind on which character I want in the middle. The ones doing the fucking will be Brigitte and Zarya. Help me out!