Doctor Nicolas was once very talented scientist.
One day he had terrible accident.
He was experimenting with liquids, but experiments with lava went terribly wrong.
Doctor fell into the container and burned almost to death.
Almost...

He was rescued by his coworkers, but he was too heavily wounded.
Only his brain and internal organs survived.
They reebuild his body in steel using advanced bionic technology, but artificial body is nothing compared to natural one.
Filled with grief and anger he lost his mind an called himself Dr Brain.
He promised himself, that some day he will have human body again.
He killed several people, but none of them was compatible donor.
Maybe Mr Steve will be?