User blog comment:B214/Question and Answers 2/@comment-24098614-20140321234015/@comment-3965848-20140324195220

There is a name for race like that, it's called Nephalem (demon/angel hybrid), normaly the angel is considered fallen seeing how normal angels are not suppose to mate.

I'm also hopping for to be able to be "close" enough with Issei without falling, although I'm not sure if she made any progress seing how she does things like bathing with him (Volume 17 life 0).