Great! We could do both then. Both of them knowing each other before and after their fall. Xaphan, of course, would have been the first to have departed considering their history but maybe met they up with Zael maybe centuries later after they absconded from Hell and are hiding? And so Zael is the first to know what really happened to them since Xaphan trusts him enough to not tell anyone due to his disinterest in getting involved with celestial politics?