Some Pokémon require special conditions or items in order to evolve. Since this is a solo game, you do not need to trade any Pokémon to evolve them to their next forms.
Darkrai, Shaymin, Manaphy, and Phione are all mythical Pokemon that appear in Pokémon Legends: Arceus. There are a few things you need to do in order to unlock them.
The recently released Pokemon Brilliant Diamond and Shining Pearl games contains a possible tease about a new variant Pokemon that could appear in the next Pokemon game. Earlier this month, Nintendo released Pokemon Brilliant Diamond and Shining Pearl, which faithfully recreate the Pokemon Diamond [.]