This is a new character!
His name is Pain and he is demonic hellhound!
and now some back story!

Excerpt from Isylum Document:

"I can't stop myself, not anymore. I'm nothing more than a puppet now......You're saying that as if I'm insane. Truth is I'm not insane, I have no control. I'll kill you, not because I want, but because I have too......How? I dunno, probably by ripping out your spine, and using it to rend your flesh until you are no longer recognizable......Yeah, maybe I am little insane, at least I always smile......."

Other parts of the documents are still lost among the rubble of Isylum.