I actually started a Supernat AU fic, because that was what my brain thought was easiest the other day.

edit:
Guys, question.
Should Karkat end up with Nepeta at the end, or should Nepeta help him escape to a clan run by Kanaya that all don't eat humans and he can be at least a bit happier there, even if it makes both of them sad. Because we do have overprotective hunting partner Equius to deal with.