Which mutant to rank up?

WolvSD

I understand that technically a 5* is better than a 4* but I’m wondering which is the overall better champ to rank up?

PIZZATIME

X-23 is so much simpler to use if u just wanna dole out bleeds and that regen can save u with the stack I don't even understand havok mechanics but whoever u have the gold and iso for but def X-23