Tor Gul, the Defiler out of border kill

You can beat Tor Gul, the Defiler in the spires of deshar when you encounter him and run out of the arena, if you go out of the border you can kill him with ranged attacks and he doesnt even Recognize that hes being attacked and is in a fight currently he just stands there and does nothing until you kill him also it Counts as killing him and he Drops Loot
i used only storm wave too kill him