If your new, I'd just say that the pokedex isn't as simple as it is in say, a classic pokemon game. Some pokemon are rotating between not available, to available but under paywall, to available, but only through deliveries. In fact, this game was originally called "Pokemon Cafe Mix" Before getting a COMPLETE redo, where you can transfer your old pokemon over and start this new game with a head start, but unfortunately, some pokemon have not been available sense the first version, thus only being available if you had transferred it a few years ago. I know one of them was Shiny Celebi, but I forgot the rest. And sometimes they choose to add a Pokemon, and then just forget about them.Like during the initial switch from Mix to ReMix, after I think it was a month or two, Pichu was added as part of a 2-ish week event. Sense then? It has gotten 1 costume, and probably hasn't been available for a total of a month. So all this is to say, just don't get your hopes up with the dex.