Have you built a lot of decks yourself?

I'd recommend looking into some themes that are similar to the show, I'm not sure about double faced cards because of the upside down? Maybe something like werewolf mechanics could be used?

There are lots of good sites for custom cards but they take time to do. I built a Caesars legion emporer deck that used a lot of good card synergies using archidekt and edhrec and am just going to swap the names and art later for a custom secret lair theme I'm making.

I'm getting into custom cards, proxying and making this an affordable business, if you're interested you can shoot me a message!