Supposedly unkillable? Thats my motivation right there. Well, that and the fact that he's (ex) Legion.. I'll be going into the DLC naked, but if it requires it, I'll restart a save and introduce him to a face full of Alien Blaster and perhaps a couple of Holy hand grenades..
Just to test out the whole un-killable theory..
(If he turns out to be a human version of liberty prime that can survive absolutely ANYTHING I can do, well, I'll go back to playing motorstorm apocalypse and just pretend he died screaming
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)