Setup Info
So here's how this works. This is a Semi-Open setup.
I've divided my Tarot deck into two piles, the Major and Minor Arcana. As seen below, I've assigned specific, fairly traditional Mafia roles to the Minor Arcana. The Major Arcana, however, have been assigned secret abilities that range from "Oh, that's new and interesting" to "What on Earth was that?" in power and strangeness. Some Major Arcana are town-aligned, some are Mafia, some are Werewolf, and some are other.
In order to keep the Major Arcana roles feeling appropriately special, I've separated them from the rest of the deck. For every seven players that join the game, one Major Arcana role is added to the setup. After that is done, I deal enough Tarot cards to give everyone a role.
Minor tweaking is done afterward to ensure some semblance of balance. It usually comes out pretty balanced, but sometimes there's six werewolves out of 16 players and that's just no good.