Derek Nemesis was the cold corrupt CEO of Alchemax. He was selling lethal bio-weapons to fascist governments overseas, and one of his employees, Warren McGinnis, stumbled onto this plot. Derek paid members of the Hyenaz gang to kill Warren before he could talk to the press. Warren's daughter, Laura became the Dark Claw Beyond to avenge her father. After defeating the Hyenas, she traced their payment to Derek. Dark Claw Beyond attack Derek and exposed him chemicals from one of his own bio-weapons. Derek would have died, had he not been a secret child of Ra's A-Pocalypse. His latent metamutant powers awakened and burned out the toxins from his dying body, but changed him into a living radioactive skeleton. Now trapped in a life support armor, Derek became the villain Pandemic, and he is solely focused on getting revenge on Dark Claw Beyond.
Pandemic is a living nuclear reactor, constantly emitting lethal levels of toxic radiation. His powers have burned away all the living tissue in his body, leaving him a sentient skeleton. His armor both keeps him alive and gives him a superhuman strength. It also allows him to focus his energy into deadly radiation blasts and fly.