I don't really have their lore finalized just yet, but I can give some basic information about him.

Jacker is a fallen Cyber Seraphim. He was cast away for his recklessness and ill treatment of Avatars (population of Afterworld). Growing bitter and even more insane left alone in the Scrapzone, Jacker comes back with a deceiving motivation to "play games".

Funny that this guy started out as a Sonic.EXE OC.