Regional forms of the following legendaries/mythicals are in the Sword Shield data as event Pokemon:

Uxie, Mesprit, and Azelf - All Fairy
Shaymin - Grass/fire
Pokedex: "Galarian Shaymin are thought to create wildfires to clear dying forests."
Cresselia - Ghost/Rock
Heatran - Fire/Fairy

You're welcome. Keep in mind I said about Regional Evolutions and you all laughed.

And yes, that's no coincidence they're all Gen 4. Figure it out.