Lillie/Games/USUM

Before or  can help Lillie, an Ultra Wormhole opens up and dumps Guzma and Lusamine onto the altar, followed by. Despite Lusamine's request for Lillie to flee, she refuses to run away and is present when Necrozma absorbs Nebby, transforming into its Dusk Mane or Dawn Wings form. When it withdraws into the Ultra Wormhole, Lillie asks the player to follow Necrozma to Ultra Megalopolis and save Nebby. Following Ultra Necrozma's defeat, she and Lusamine bring Nebby back to Aether Paradise so it can heal from its injuries.

Later on, after the player has defeated Ilima at Hau'oli Cemetery, she can be found back at Mahalo Trail with Nebby. As in Sun and Moon, Lillie suggests that Nebby can join the player in the hopes that they can calm Necrozma's fury if they encounter it again, allowing the player to capture it. After Nebby is caught, Lillie will give the player a Solganium Z/Lunalium Z, which she had found being held by Nebby.

After Team Rainbow Rocket's takeover of Aether Paradise, Lillie visits the player's house and asks for their help in saving Lusamine. She is later revealed to have become a Pokémon Trainer herself and acts as the player's partner in a Multi Battle with Faba and an. Throughout Episode RR, she mostly supports the player by healing their Pokémon.

After Episode RR, Lillie can be visited at Professor Kukui's laboratory on, where she will accept to join the player as a Multi Battle partner at the Battle Tree.