Soul Jacker is the "Worlds Deadleist Man". He was tasked to help his master, Dr. Necros,` launch a toxin that would turn every last human being into brainless savage zombies. He first got into combat with Dark Owl while escaping with the toxin and soon killed him. He encountered Aaron while trying to steal a rocket Launcher and easily defeated him due to his lack of experience. Later in their second encounter Aaron was Able to defeat him and even disable the missle containg the toxin. STAN says he is still alive but had't been seen since. It is most likely Mr. Hall incarcerated him.