>>49456320You will get.
Wave 1: Callback retro costumes
Wave 2: A contextless legendary added that the player can get pretty early into a playthrough, and also your pokemon can now walk.
Wave 3: More costumes, including the coomer swimsuits and crossover references.
Wave 4: A pretty substantial DLC questline, complete with new story, but is completely irrelevant to the main story. You fight Clan Plasma, which ends in a pretty legit fight with Ghestis' ancestor, with a totally unexplained Genesect, for example. You don't get much for doing it, but low level runs of this become the defacto challenge for the game.
Wave 5: Some repeatable missions that allow you to cycle some resources into eachother. Also a single weird costume that means a lot to the one guy on the dev team that pushed for it.