So he had been a part of all that ... And from the looks of it he was in a generation that did alot of shit. I guess he got his life back just to find out he doesn't want it ... Ironic. But if he wants to return, instead of killing Kei shouldn't he instead kill himself. Though I don't think he tried to kill Kei but just shoot Kei's suit knowing he wouldn't die (though I am not positive that the suit blocks bullets, it doesn't block sharp objects so ...)