i dont know where to post this but i found somthing out bout paarthurnax glicth on 360 i just killed him and no he not couse by a glicth that makes him unkillable the min you start the quest it if you use dragonrend on him or talk to him that he should die couses the glicth cuz i did that the 1st 2 times he was unkillable but then i decided that id just go up and start hiting him with my axe and he flew up trigged battle killed him then quest is done