This particular mind game set in motion a trend that would become The Undertakers signature sub-gimmick, if you will. No matter how much damage he took, no matter how bent on destruction his opponent was, no matter how savage a beating he took in his matches, and no matter how many times his opponents presumed that The Undertaker was gone, he would keepcomingback. From being dead and buried forever at the hands of Kane, to Mark Henry and the Great Khali presuming to have destroyed him, to countless others over the years who have tried to vanquish him permanently, vignettes of The Undertaker returning would appear soon after each presumed ending. When you can bury someone alive, only for their hand to burst through the dirt, you know you're dealing with something that may be unkillable. Undertaker did this time and time again, rising from the dead to play more mind games on his attackers. Why else do you think his catchphrase how can you kill that which cannot be destroyed? still works for him in an age of such widespread fan cynicism?