User blog comment:B214/Question and Answers/@comment-24017079-20131006011202/@comment-24017079-20131006012233

I don't know about that.

Azazel warned Issei not to try fighting Samael, saying that he won't be able to do anything to Samael if Ophis couldn't.

That implied to me Ophis couldn't do anything about Samael, not that she wasn't trying.