Lore wise it’s Reaper and its not even close. He’s a super Soldier who is literally unkillable, can pull shotguns out of nothingness and can morph into gas. There’s nothing the other dps heroes can do to actually beat him(Besides inhale him maybe). He can probably kill them before they can even react because he’s canonically snuck up on both Winton and Soldier.

Genji gets second place tho.