Hank J. Wimbelton finds himself in the world of MHA nuff said (On Ao3)

For every action, there is an equal, and opposite reaction. Order creates Chaos, Sanity creates Madness, and Peace creates Combat. And every fate given by the universe, no matter how Improbable... can and will come to fruition. (I own neither Madness Combat nor My Hero Academia)

Izuku J. Midroriya, 28 years old, has been the vigilante/anti-hero, Nexus, for 7 years. He's been a mercenary and is out for vengeance against his mothers killer, who is yet to be found, watch as he gains enemies, allies, and friendly enemies. (Now on AO3!) Moved to ao3,

The infamous trio has been thrown through reality into a strange new world. A world of heroes, villains, and everything in-between. A world that knows nothing of the horrors in Nevada. These horrors will soon follow them. There will be no kindness, nor mercy. Only Madness.

Awoken in a strange lab with no recollection of memory, identity or purpose. A rebel organization found him and gave the subject a purpose. Now, more victims to the slaughter with no regret, no remorse, no reason...only madness. Wielding improbability he held and gave uncertainty onto his enemies who made him.