Sometimes, after using vengeance on my warrior, I will die before the effect expires but when I resurrect, I will still have the vengeance debuff on me which will expire, causing me to die yet again. I believe this is an unintended bug caused by the debuff not being removed on death (although it is pretty funny for it to happen at the end of an sPvP match and then to resurrect in the next map and immediately die).