>>58535526You can get everything in-game on your own except for Slurpuff, Scizor, Aromatisse, and non-Galarian Slowking.
There is an alpha Steelix you can catch but you only have the one encounter to do so. You can find wild Alakazams and Machamps in the last zone post-game. You have a side quest that lets you catch a Gengar. You can find wild Trevenants and Gourgeists.
There is a guy who will trade you your normal Slowpoke for a Galar Slowpoke. Then a girl will give you both items needed to evolve it either into Galarian Slowbro or Galarian Slowking. If you picked the Slowking, that will still count towards your Dex entry as a "general Slowking" entry.
So if you're trying to make a living dex or just your own persona completionist preferences, you WILL need to trade. If you are doing it just to complete the dex for the shiny charm, you only need to trade for the first three Pokemon in my first sentence. If you fuck up with Steelix, Gengar, and Slowking, then you will need to trade for them as well.
Also, someone in the game will gift you a Spewa after a side quest and it is the only Spewpa that will evolve into Marine Vivillion. Don't release it.
