Mister Freeze

Cryogenically froze his dying wife until a cure could be found
Illegally used GothCorp funds to do so, the CEO destroyed most of his equipment;
Thrown into a batch of chemicals, permanently altering his physiology
Body could no longer survive in temperatures above zero degrees;
Built a cryo-suit that kept his body at low temperatures & tripled his strength
Turned to a life of crime, became a cold, sadistic psychopath