Who should I rank up for the x-men sos objective?

Will3808

Apparently my x-men roster is very limited, so I'm either going to need to use my 6* r3 gambit (who I've tried and he's terrible because you have to do a lot of blocking to build charges) or I need to rank up someone. My options are a 5* r3 sig 40 storm px, 6* r1 unduped professor x, or 6* r1 unduped white magneto. I leveled up professor x a while ago, but I don't like him, which is why he's still at rank 1. I would be taking storm px to rank 5 and most likely the 6*s to rank 2 because I'd really only be using whoever I rank up for this fight. Comment if I should rank them up further.

willrun4adonut

Rank 3 one of the 6*s

White Mags. I think r2 would be pretty difficult.

Talha305Raja

Rank 3 one of the 6*s

Take OG storm to r3, i one shot him using her at r3, she's a cheeeeeese option for this fight

Will3808

@Talha305Raja I don’t have og storm as a 6*

hyp3r05

Rank 5 Storm PX

I did the storm px with the 6* at r3 and she killed it. The 5* at r5 should do it, even easier if you can ascend her as well.