Have you tried Moriarty the Patriot? It's a Holmes adaptation but from Moriarty's point of view. Very slashy including brother incest if that's up your alley. It's two seasons and the ending is open season for fic, pretty much.

I'm also very curious to see it anyone shows up wanting Vanitas no Carte, which is period vampires. It is...extremely anime, with pretty and interesting people engaging in all sorts of hilarious or melodramatic circumstances. Lots of horny blood drinking and ships of various combinations. Only 12 eps, the last one is airing this week. The setting itself is really interesting too and I could see someone really making use of the new worldbuilding tag (if that goes through?).