A Russian serial child killer who was executed without trail by gunshot, survived, and was recruited for a brutal KGB experiment which gave him enough super powers to make him a minor god.
Omega Red has retractable tentacles in both arms, that allow him to retrain, strangle, crush, whip, you name it, all while draining the life force of anyone touching them; unfortunately, they also slowly poison him, requiring him, vampire-like, to drain the lifeforce of others to sustain his own life.
He’s also superhumanly strong, fast, resilient, agile, etc. The usual supervillain repertoire.
AND he secretes toxic pheromones called “death spores” that kill normal humans nearby nearly instantly.
Essentially he’s the (more) nightmare version of Andrei Chikatilo.