Black Noir (The Boys Amazon) vs David Dunn (Unbreakable/Glass) vs The Mountain (Game of Thrones) vs Bane (Nolanverse) vs Mr. X (RE2 Remake) vs Reinhardt (Overwatch)
No prep time, battle takes place in a public park. Everyone has standard gear/weaponry, and are bloodlusted. Fight to the death/incapacitation.