>>104930897He's as immune as any other person would be. If it's a thing you can fight with strength of will, he could fight it with that. If it's a thing that attacks and forcibly alters the body, it would have to forcibly alter Kryptonian cells (and he's 100% as tough inside as outside).
Don't assume "vulnerable" means "weak". Magic isn't like kryptonite, he doesn't fold like a wet paper bag just because something is magic. Etrigan blasted him all the way to the moon with fire once, and he was perfectly fine afterwards. Because while that fire came from magic, it was still fire, and worked like fire. Which meant it had to deal with the fact that Superman is superhumanly durable, and a ball of fire isn't going to do shit to him.
