Gladion just arrived in the Ultra Wormhole with Ash, Lillie, Kiawe, Lana and Barbara thanks to Solgaleo to save Gladion and Lillie's mother, Lusamine, who merged with a Nihilego. But when they arrive, Lusamine attacks them with her Pokémon, so Kiawe, Lana and Barbara stay behind to battle against Lusamine's Pokémon while Ash, Gladion and Lillie move forward with Solgaleo. But when they arrive towards Lusamine, she attacks them with the Nihilego's attacks and they don't have time to dodge.