User blog comment:B214/Question & Answers 5/@comment-82.199.209.161-20160302154156/@comment-82.199.209.161-20160302163449

So, it can't be used on the opponents, but it is possible to use on their attacks.

I think, it's not about God-class, it's about the divinity of the Gods themselves, that protects them, in vol 16 it's mentioned that gods have divinity(since Balor said that he lost his divinity).