Mutant rankup gem decision?

Ezra7676

I have colossus and OR maxed and r2 Domino. Looking for most useful monthly questcand Act 6 champ. Strongly leaning towards AA.

Edit- r4 to r5 gem

Sarvanga1_

AA

Will3808

Take up AA. He’s the best option out of who you haven’t ranked up yet.

pseudosane

AA and havok.