For anyone who doesn't know, when you go to kill Izual, and he's surrounded by a bunch of other monsters, if you just concentrate on Izual and kill him, all the other monsters in the area die (similar to Shenk).
Just a little info for those of us who never tried it.
but if u didn't know, izual usually has a lot of hp..... a lot more than shenk so it would actually be better to kill monsters nearby and actually he usually doesn't have A LOT of monsters nearby
If you have massive life leech or some hp draining spells, it will work out very well for you. I always attack him first and say fuck you to the rest of the guys. With my zelaot (botd zerk, exile, enigma setup), he had no problem doing this.