In the late 1940's, Jerome T. Hawkins was a young American man suffering from severely debilitating and unsightly birth defects, leaving him with a misshapen head, stumps for feet, and an atrophied hand. He had it tough from the beginning, and found solace in pulling the wings off of flies with his good hand, and plotting revenge. Dark, morbid revenge.
After persuading his 6th carer to commit suicide with his manipulative words and twisted thoughts, he was locked up in a ward for the criminally insane. Without a body to back up his brain, he was all but helpless.
That is, until, he was put into solitary for convincing a young female nurse that she needed to reduce her wrists to ribbons for looking at him with distaste and judgement (such were his powers of persuasion).
Solitary was, in this case, an old boiler room-cum-storage closet, and in it were all the makings of a mind-control device. An old wheelchair, a set of modified 2-way headphones, a few simple inputs on the makeshift joystick and console, and he would have his subject at his complete and utter disposal. He bid his time until the biggest and meanest brute of an orderly came to do "obs", and within seconds the man was under his control.
Breaking from the ward, Hawkins made straight for the darkest and most depraved streets and neighbourhoods the city could offer him. With the help of black market surgeons, and a bit of persuasive talk, Hawkins found himself tinkering about inside his ward's skull, making numerous tweaks and adjustments and improved response time significantly - reducing lag to nothing, tuning host with parasite perfectly.
He was soon introduced to the underground fight clubs, which in turn led to his discovery of his ability to easily dispatch any opponent without as much as a scratch on his own deformed body. This made him a powerful adversary, because as soon as his brain melded with another's brawn, there was very little that could stop either of them.