pretty simple really, once hes been looted and your through the gate after a little while he will turn into his normal self again its what he really was, well dont have to be through the gate but yeah, most nof u probably know this but he came to Baron (ages ago) asking him to help conqure stormwind, because the king was gone missing and the child which has stormwind now is no match for the baron, so he came asking for help to slay him, the baron refused his offer saying his time will come i may do it on 1 condition, u help me defeat the living! that come to my lair. and so its magistrate barthilas became who he is guarding the east wall gate with tghey key until u kill him and the spell baron put on him to help him along the way failed!