Hogaak, Arisen Necropolis is an awesome card purely from a card design perspective: It's an expensive creature that can only be cast using a combination of different mechanics
Additionally, the Night Joker attack allows you to use any attacks belonging to another of N's Pokemon that you have on the bench
Sets that primarily take place there : Innistrad , Dark Ascension , Avacyn Restored , Shadows over Innistrad , Eldritch Moon , Innistrad: Midnight Hunt , and Innistrad: Crimson Vow Planeswalker natives (with planeswalker cards) : Arlinn, Sorin, and Tibalt Innistrad is a plane inspired by the horror genre, especially the subset of gothic horror
While best can be subjective, the Roronoa Zoro [Flagship Battle] OP01-025 is widely considered the most valuable card in Romance Dawn
Black and green does its thing