Board Thread:Manga/@comment-26056057-20160509020829/@comment-27321453-20160518104753

An experienced shifter can get his/her brain blown out, a blade through the neck (and chest)  and still survive  that's all thanks to the "transfering consciousness/brain functions to the body's nervous system" skill (or whatever)  as we've seen Reiner do it TWICE so it's safe to assume that you can't kill an experienced shifter unless you either sever the spinal cord and deplete its fluids, saw the body in half or just blow the shifter's whole body to pieces! (had the Survey Corps soldiers stabbed Reiner's actual body's back with more Thunder Spears and exploded them, Reiner would have definitely perished). As for Eren, I don't think he's experienced enough or even know how to transfer his consciousness to his body so I believe he would die if his head got blown off like Reiner's.