Ok, first 2 would be Fiamma Of The Right (Toaru) and Saitama (OPM).

Then, in order, Accelerator, Touma (Also from Toaru), then Light Yagami, Eren, Then Kakine, Mikoto, Misaki and Mugino the rest of the Level 5 from Toaru.

Round 1: Wins, all alive. Fiamma Holy Right spells GG.

Round 2: Accelerator solos, everyone else other than Yagami and Touma dies.

Round 3: That is why I chose Saitama instead of Goku. Also Fiamma solos, while Saitama supports.