Primal Stone Location

Primal Reversion is a transformation sequence similar to Mega Evolution that only Kyogre or Groudon can undergo. Primal Reversion allows them to regain their Primal Form at the start of the battle. They need to carry a special item for this to activate. Unlike Mega Evolution however, Primal Reversion activates immediately as soon as the Pokemon is sent out to battle. Another key difference between Primal Reversions and Mega Evolutions is that you are not limited in having one Pokemon in Primal form in a battle. You can have two Primals at the same time.

Kyogre and Groudon will be carrying their own Primal stones after getting them in their respective versions of the game. The general location of Kyogre and Groudon's Primal Reversion stones will be listed here; the exact methods on how to acquire them will be updated later.

Kyogre

• AS: Kyogre's carrying it
• OR: Mt. Pyre

Groudon

• AS: Mt. Pyre
• OR: Groudon's carrying it

Reference: Serebii.net