[It's more the shock of someone suddenly being next to him than the nasty aura that makes him jump back, really. It's not really a problem for him, given he's been stuck with Ghost for ages. His reaction is more concern and bewilderment than fear or hatred.

...Or, it will be, once he stops flatlining over the fact there's a living person right in front of him. He hasn't seen one in who even knows how long.]

...H-How...You're...a-al--? [Nope, can't get more than that out. Did you ask a question? He probably missed it.]