Next rank 5?

SlayerKing

I have sentinel, Arch Angel, Hyperion, sym supreme, namor ( low sig level ), colossus, Ægon and Gwenpool so who’s the best option for AW attack and UC monthly event quest

10or_Strong

Archangel, Hyperion, Colossus, or Aegon will all do really well for you in a wide range of content. Probably as an overall choice I'd say Archangel or Hyperion are you best bets for total usefulness. But don't sleep on Colossus either1