Oh, I love the crossover idea! But I also have no idea what canons it would work for. It would have to be something that's also long and twisty and murdery to be worthy of Bern and Lambda's attention. ... Something like Dangan Ronpa, maybe? Though I've been functionally out of that fandom because I can't afford the third game.

Someday, I will finally write the Ange/Mammon that I've been thinking about for ages. Someday.