Magneto is absolutely disgusting. He'll do your team much better than captain america.
I've decided my team will be Iron Man/Amaterasu/Dormammu. Iron Man is all around very strong, his tri jump is fantastic and he seems to build meter well, so I'm thinking he'll be my point char. Ammy does really underwhelming damage compared to the rest of the cast, I'm putting her on second because she needs meter to do well. Her slowdown super seems powerful though, I'll be testing it out more in my matches.
They actually fully intended X-23's infinite, it's included in her guide.