And here we have the master and mind behind the Death Battalion: Brain!
According to the original character description, Brain was a Nazi Fifth Columnist, disguised as Warden Loomis, warden of "El Catraz" (Sheesh) high security prison for super criminals.
I thought I'd update the character a little. Let's say Loomis was once a petty thug who ended up in prison as a teenager. With no family or friends, he grew up moving from prisons, to sanitariums, to correctional institutions... all of which, like most prisons do, schooled him in crime. Whenever released, it wouldn't be too long until he was sent back, each time for a worse crime than before. Resolving to better his chances at never getting caught again, he educated himself in the prison library and started forming a gang. He feigned a change of heart, confusing and tricking his assessors and evaluators, who eagerly accepted all the praise shown them for having 'cured' such a dangerous individual. Little did they know that all their methods, all the beatings, all the humiliations had only served to turn Loomis into a criminal mastermind. After 10 years, he was out. He was free.
Quickly bribing the authorities to get his former gang members free, Loomis was soon on the rampage yet again, this time covering his tracks and building himself a criminal empire.
However, one fateful night, a rival gang attacked Loomis' secret warehouse, full of contraband and stolen items. There was an explosion, and Loomis was almost fatally injured.
Through his many connections, Loomis was able to save himself. Brilliant surgeons managed to transplant and preserve his brain inside a mechanical probe, with a robotic body as its vessel.
Learning that it had been Mr. Scarlet who had tipped off the rival gang, in the hopes that the gang war would stir the corrupt police force out of their apathy, the creature now known only as the Brain, set about planning his revenge. Assuming the identity of El Catraz's warden through hologramatic projection, Brain set about secretly recruiting all of Mr. Scarlet's worst enemies...