Question: pokemon ultra sun and moon where to get red orb?
Answer: Kyogre needs to hold the Blue Orb to undergo Primal Reversion, while Groudon must hold the Red Orb instead. You can purchase both items from Antiquities of the Ages in the Hau'oli City mall in Pokémon Ultra Sun, Pokémon Ultra Moon, Pokémon Sun, and Pokémon Moon.