That Pokemon Legends: Arceus would contain regional Pokemon didn't really come as too much of a surprise to long-term fans of the series. After all, both Alola and Galar received them in recent years, and so it only made sense for Hisui to have its own regional forms as well. Indeed, Hisuian Pokemon were ultimately revealed fairly early on in the game's development, but that's not to say that there weren't still one or two big surprises in Game Freak's latest Pokemon game.