Best story/event quest for my roster

StarlordisWicked

I’m at a crossroads. After a year of heavy grinding (every milestone on 90 percent of the arenas) I’m wanting to focus less on arenas and buying shards/crystals with units earned and more on in game content to level my best heroes. I’ve completed 6.1 to earn cavalier title, but have not explored anything past 5.1. Trying to figure out if I should explore chapter 5, complete LOL, complete variant micro realms or variant ultrons assault. I’m not sure what my roster is best suited for.

6 star: Symbiote Supreme, Proxima, Kingpin duped, Thor Rag duped

5 star rank 5: Hyperion sig 100
5 star rank 4: Void sig 140, AA sig 130, SL sig 150
5 star rank 3: Quake sig 60, Proxima sig 40, KP sig 60, GP, OR sig 100, Corvus, CA IW

5 star rank 2: She-Hulk sig 60, Iceman, SG, Rogue sig 40, carnage sig 60, venom, EMma sig 80, RH sig 40, WS sig 20, Hela, Doc Ock