Which Mutant to Rank up ??

1927_2BPunished

I have a 4* AA 4/40 + awaken + 99 Sig. Lvl.. I also have a 5* IceMan 2/35 + unawakened . Should I rank up and max out AA first ? Or focus more on ranking up IceMan ? At this time I don't have enough items to rank both.

FR33_HUG5

I’d go for Iceman. Poison, bleed and incinerate immune.