Thank you sirYou can't kill him. If you choose to fight him, he's one of the tougher fights in the game (esp if you fight him early), but he runs off before he dies. He drops a quest item, the Magical Sapphire, but you can get it non-violently by passing some trait checks at the magical barrier. And you don't need the Magical Sapphire, it just lets you leave the grotto before beating the boss.