It physically reappeared where it and Nebby tried to escape from Necrozma through the Ultra Wormhole, after injuring Nebby, Necrozma tried to absorb Lunala, but it was able to dodge and follow path to the Altar of the Sunne.
After arriving at the Altar, Lunala is chased by Necrozma and the two do battle, Lunala receives aid of the Ultra Guardians and Tapu Koko in the fight and together they can weaken Necrozma, but after the Prism Pokémon attacks it with surprise with Metal Claw, Necrozma weakens it and takes advantage to fuse with it and assume its Dawn Wings form. After Nebby appears and defeats Dawn Wings Necrozma, Lunala is freed from it, but is weak due to the fusion, Matori attempts to capture Lunala and Nebby, but they are saved by Ash's Pikachu and Gladion's Silvally.
After Necrozma absorbs Nebby and escapes through the Ultra Wormhole, Lunala is taken to Ultra Guardians' base to be dealt with, but only regains its powers after Ash, Gladion, Kiawe and Lana share the power of their Z-Moves with it.
After recovering, Lunala takes the Ultra Guardians to Poipole's homeworld through the Ultra Wormhole, hoping to find Necrozma and find a way to free Nebby from it. Later, Necrozma reappears and Lunala battle against it.
After the Ultra Guardians tried and failed to free Nebby from Necrozma using Z-Moves, Lunala continued to fight the Prism Pokémon until it finally freed Nebby. In order to help Necrozma restore its powers and resume its original form, Lunala entrusted the Lunalium Z to Gladion and both used the Z-Move Menancing Moonraze Maelstrom, transfering the energy to Necrozma and fully restoring the Blinding One to its glorious form. After Necrozma restores Poipole's homeworld, Lunala returns to Alola along with Nebby and the Ultra Guardians. However, its whereabouts after they return to Alola is unknown.
Lunala appears in some of the photos in the Aether Foundation during the Utra Beast conflict and the Necrozma conflict.