- Uxie will appear more frequently in raids in the Asia-Pacific region.
- Mesprit will appear more frequently in raids in Europe, the Middle East, Africa, and India.
- Azelf will appear more frequently in raids in the Americas, and Greenland.
- Sources
Uxie, Mesprit, and Azelf to appear in a special raid event! – Pokémon GO
pokemongolive.com