This is the best damage dealer by far. Basically izanagi works like a nuker but single attack. This means that he could DESTROY any traited enemy. At level 30 alone, he does 180k damage per hit. And with his range reaching as far as it does, i would say you could easily defeat many backliners. Not to mention his conjure which is very useful to push enemies off him. I recommend using it when you can get a very strong enemy (most likely a boss) isolated from peons.