7* mutant AG picks

I have a materials to r2, a r3 mutant gem and enough sig stones to go to 75 (5 mutant/70 generic). My first pick is obv onslaught but just want everyone’s opinion on if I’m sleeping on someone else, or if I should hold it.

I have a materials to r2, a r3 mutant gem and enough sig stones to go to 75 (5 mutant/70 generic). My first pick is obv onslaught but just want everyone’s opinion on if I’m sleeping on someone else, or if I should hold it.