Batman - strongest version, canon/non-canon doesn't matter. Morals off , bloodlusted. Prep of 6 months. All gear gadgets are supposed to bring hellish pain/death instantly and not those lame standard gears.

Doom - standard , no prep.

Batman heard Doom killed his parents by going back in time.

Fight starts at 1 am in Gotham alleys, random spawn.

Death Match.