It's Solgaleo, one of the Light trio along with Lunala and Necrozma. It's the Sunne Pokémon that evolves from Cosmoem. Known as the Beast That Devours the Sun, it has been honored as an emissary of the sun. Its body is capable of holding a vast amount of energy and glows when active. The intense light it radiates can make nighttime look like midday. It can create Ultra Wormholes to travel to and from Ultra Space. Along with its counterpart Lunala, it can create Cosmog.