[Cao Pi tips his head slightly in acknowledgement] Yes, I suppose that would be an important detail. In my experience, it is less a prohibition and more whether they feel like it - our gods can be capricious and disinterested in the affairs of humans.

Here, though, they have some limitations. For example, no matter how powerful our creator-gods may be, they cannot free us from Orochi's world and send us back. It is somewhat distressing to consider if you put any stock in the gods being competent. [which, given the dry, dry tone of his voice, he doesn't] But, on the other hand, most of the demons roaming abroad can be slain with a very basic sword, so there's that.