To stop a grave threat from unleashing havoc upon all the realms, an infamous rogue warlock, the king of demons, and a student of a lost arcane art must embark on an epic quest to the most dangerous part of Equestria. Well, dramatically speaking.
Honestly, how is this the first crossover anybody's written with The Owl House? I literally had to make the group. Seriously, the show is incredibly funny and well-written, one of the best cartoons to ever come out of the US, I'd say. If you haven't seen it yet, Disney has the first episode freely available right here. You should be able to appreciate this story well enough after just the one. Oh, and the coverart is by Kurukoo on Deviantart.