If your talking just stepping on a dudes face it'd take someone over 500 pounds to crack the skull so a death fat or the big vampire lady from resident evil stepping on you could kill you. If we're talking a kick or taking it off and swinging it you can absolutely kill some one with a high heel, a women, Ana Trujillo, is in prison for murdering her boyfriend with a stileto. Fucking matpat had the strength to break a skull by swinging a stileto in a video.