Season 8 - Master League, Master League Classic, and the Element Cup

The Master League, the Master League Classic, and the Element Cup will run from Monday, June, 28, 2021, at 1:00 p.m. to Monday, July 12, 2021, at 1:00 p.m. PDT (GMT −7). Battle during this time to receive twice the Stardust from win rewards and end-of-set rewards.

Master League - No limit on Pokémon CP
Master League Classic - Only Pokémon that haven’t been powered up with Candy XL are allowed.
Element Cup - Only Pokémon that can evolve and that are the first in their Evolutionary line will be eligible for this cup. True to its name, only Fire-, Water-, and Grass-type Pokémon are allowed. Pokémon of multiple types are allowed so long as one of their types is Fire, Water, or Grass. The CP limit will be 500.