I would be a good level of around 50 - 45.

He is REALLY annoying with his renew. He did it to me EVERY TURN. The bastard never stopped until one time where he was just about to cast it but I let out a massive onslaught of my blade and WHAM he was dead.

The best way to beat him is to at least be able to kill the bombs in one hit or two. That way have one person attacking the Bomb and one attacking the mini bombs. That way all it will do is call its bombs while you take 9000 damage on it per attack. You're gonna do this for awhile probably until it stops summoning them then you can kill it without it casting renew.