The five Nauctis factions showed up on the MagicCon Detroit 2027 schedule before Wizards previewed a single card: Humans, Merfolk, Sharks, Decalids, and Desolators, each racing to find the Sunken Realms. Here's who each faction is, what their Oceanic League blurbs give away, why the humans have no green mana, and why Nauctis: The Sunken Realm starts Magic's first story arc after Jace Beleren's death.