Clark nodded at Diana's information. "I met Lois the first time she came here. She was being attacked by vampires. I thought she was Chloe at first, but... it's really Lois." Then he turned his attention to Oliver's question. It was certainly a valid one. Zod and Prime were huge threats, ones they'd have to deal with shortly.
"I haven't met either here yet, aside from the message boards. I know they are from Krypton.. just like myself, Kara, Jor-El and Superman. So.. I think the same rules apply. Green kryptonite, if we can find some. And of course they would be vulnerable to magic, as we are."