you don't really need to fight them fair. make everyone invisible, approach in tern-based mode, go up to the main guy and start the fight. you need to kill just him, the rest will disappear after he dies and they get their turn
so
what i usually do is place the invisible party where the main guy will teleport after he gets his first punch upstairs, then enter the fight one by one and kill him before he does something stupid))
the clown head is in the ruins before the main bhaal temple