On the other side of the Ultra Wormhole, Lunala and the Ultra Guardians arrive in a dark world. Ash notices Poipole's excitement then the Ultra Guardians are attacked by a stream of purple liquid. Kiawe has Charizard reply with Flamethrower and when the smoke clears, the attackers are revealed to be several Poipole, who resume attacking them with Venoshock. Ash tries to tell the Poipole that he and the Ultra Guardians are not the enemies and just want to save Nebby, but they don't listen. Ash's Poipole goes on to explain to its kin, and they stop their attacks. Then, Naganadel comes out of the hive and cries out. Ash's Poipole is happy to see Naganadel as Lana notes its resemblance to Poipole. Unknown to the humans present, Stakataka's pokeball is shaking as he he reacting to something that is shimmering deep within the cave.
Rotom notes that it has no data on Naganadel. Then, Naganadel collapses, worrying Ash's Poipole. Despite Gladion and Y/n's concerns about losing track of Lunala, Ash is determined to help Naganadel and goes to its side. Lana, Kiawe, Lillie, Sophocles, and Mallow all follow suit, forcing both of them to go with them.Meanwhile, in Alola, Burnet tries to decipher the Altar of the Sunne mural to find the connection between the "Blinding One" and UB Black. Back with the Ultra Guardians, they check on Naganadel's condition and conclude that it's tired. Mallow offers some Sitrus Berries, but Naganadel refuses them until Ash's Poipole convinces it otherwise. Naganadel eats the Berries, and a voice thanks them. As the Ultra Guardians wonder where the voice came from, Naganadel reveals itself to have been the one who said it, and Gladion recognizes it as telepathy. Naganadel asks them if they want to save Nebby and Ash confirms it. Kiawe states that UB Black possessed Nebby and fled to this world, to which Naganadel asks if "UB Black" is Necrozma. As Ash repeats the name, Naganadel requests for Necrozma to be left alone, stating that they need Necrozma's power. Gladion and Lillie ask for an explanation, and it uses telepathy to show the Ultra Guardians a vision of the past, back when the world was shining with light, with flowers everywhere. Naganadel explains that the world was once filled with light rained down by Necrozma. Ash sees Ultra Necrozma and realizes it is the "Blinding One". Then, the vision switches to a meteor falling to the ground, which Mallow and Lana note that if it was to hit, then it would cause a huge explosion. Necrozma collides with the meteor and destroys it, causing a bright flash of light, and when the light clears, Necrozma is revealed to have changed form and turned black; Gladion makes the connection between the "Blinding One" and UB Black.
Naganadel explains that Necrozma protected the world, but at the cost of its light, causing it to enter a deep slumber. Without Necrozma's light, the plants withered and the lands became desolate. The Poipole and Naganadel were forced to live huddled together to make use of the little light that was left. Naganadel tried to find a new place for it and its kin to live in but was unable to do so as it was too old. Then, it shows a lone Poipole flying into the distance as Rotom recognizes it as Ash's. Naganadel reveals that Ash's Poipole set off on its own as the vision ends. Naganadel continues, stating that they had given up hope on their world, when Nebby and Lunala wandered into it, causing Necrozma to awaken from its slumber to absorb their light and heal itself. Naganadel then turns his stare to Y/n.
Naganadel:Young man. I feel a strong ultra aura emanating from you. Are you in possession of an ultra beast?
Y/n:Yeah I am. Why?
Naganadel:Please bring it out.
Y/n reluctantly sends out Stakataka. As the beast comes outc Naganadel staresvat him as if checking him out before he nods towards one of the Poipole as she flies away. A few seconds after she comes back and hands Naganadel something.
Naganadel:Long ago when Necrozma feel into his slumber we found something very peculiar. It was radiating with his power and was unresponsive to use and even me but u realized when you all arrived it started to shimmer with a powerful light. I now know that this crystal has chosen you. Please accept it.
Naganadel drops the shard into Y/n's hands as the group gasps at this.
Y/n:A z crystal?!
Naganadel:Yes we call it the ultraium z. A z crystal that can only be used by ultra beasts. I am too weak to use it so I want to pass it onto you and your Stakataka.
Y/n:Thanks Naganadel.
Then, a loud noise is heard as Ash, Y/n and Gladion run outside to see Lunala falling to the ground, as a result of a Prismatic Laser from Dusk Mane Necrozma. Gladion rides over on Silvally to assist Lunala, only for Ash, who tries to warn him. Necrozma jumps on top of Lunala and prepares to attack it with Metal Claw, but Silvally fires an Air Slash, causing Dusk Mane Necrozma to back away from Lunala. Dusk Mane Necrozma attacks Silvally and Lunala, but they both dodge. Gladion orders Silvally to use another Air Slash, but Ash stops him. Gladion states that they cannot leave Dusk Mane Necrozma to its own devices at the risk of losing both Nebby and Lunala. replies that they cannot drive Necrozma away and leave this world in its current state either, so he and his friends agree to save everyone. Ash figures that Necrozma craves Ultra Aura, almost like it was starving; and he has a flashback to when he, Lana, Kiawe, Lillie, Y/n and Mallow shared some of their lunch with Sophocles.Ash makes the same Pokémon puns he made back then to explain what they should do, to Gladion's confusion. Lana and Mallow explain the meaning of Ash's words, and Sophocles figures that they can give Necrozma their Z-Power to make it release Nebby; Gladion agrees to go with Ash's idea.
Back on Ten Carat Hill, four Team Rocket Grunts and Gozu descend to confront Kukui and Faba. One grunt attempts to fight Kukui and Faba, but Gozu steps in and sends out his Aggron. Gozu reaches into his uniform for a necklace with an attached Key Stone, and promptly Mega Evolves Aggron into Mega Aggron. Mega Aggron's Heavy Slam defeats Kukui and Faba's Pokémon in one hit, much to the two's shock. Meanwhile, Jessie, James, and Meowth watch the events unfold from their balloon. James and Meowth clarify that Necrozma possessed Nebby and fled through an Ultra Wormhole, and Lunala and the Ultra Guardians went after them. Jessie declares that they should capture them. James asks Jessie if she plans on going through the Ultra Wormhole, to which the latter replies that instead, they're going to wait for the Ultra Guardians to return to capture Nebby and Lunala.
In the Ultra Guardians' base, Burnet manages to decipher the text and reveals that UB Black is the "Blinding One" who lost its light. Furthermore, she also uncovers more details about the legend: it wasn't just Solgaleo and Lunala that shared their light with Necrozma, the people and Pokémon of Alola also shared their light with it.
Back in Poipole's world, Lunala and Dusk Mane Necrozma resume their battle as Kiawe, Lana, Ash, Y/n and Gladion all charge up their Pokemon's Z-Moves and unleash their respective Z-Powers.
Y/n:Archie soaring feather blade!
Ash:Pikachu gigavolt havoc!
Kiawe:Marowak Inferno overdrive!
Gladion:Silvally break mneck blitz!
Lana:Popplio hydro vortex!
The 5 Z-Power blasts combine into a single beam of energy that hits Dusk Mane Necrozma.Instead, Dusk Mane Necrozma absorbs the Z-Power from the four Z-Moves before attacking Ultra Guardians with Prismatic Laser.
Back in Alola, the residents of Melemele Island, Akala Island, and Ula'ula Island get ready for the Manalo Festival as an eclipse begins to form. On Ten Carat Hill, as Gozu receives a call from Matori ordering him to get back to the helicopter. At Gozu’s command, the Team Rocket Grunts leave him behind to continue his battle against Professor Kukui and Faba. Gozu states that the eclipse will bring about the era of the Matori Matrix and has Mega Aggron use another Heavy Slam. Kukui asks Faba to keep a secret from Ash and his classmates as he sends out Incineroar and has it use Darkest Lariat, blocking Mega Aggron's attack. Gozu tries to have Mega Aggron use Flash Cannon, but Kukui has Incineroar use its signature Z-Move, Malicious Moonsault to defeat Mega Aggron, reverting it back into a normal Aggron. Faba thinks about Kukui's words, and then, he sees the Masked Royal's image in Kukui, realizing that two are the same person. Excited by this revelation, Faba reveals that he's a big fan of the Masked Royal and opens up his lab coat to reveal a Masked Royal shirt. Kukui is surprised by this and invites Faba to do the finishing pose together. Gozu recalls Aggron and retreats back to the helicopter. The Matori Matrix attempts to enter the Ultra Wormhole, but they are hindered once again when Tapu Koko uses Dazzling Gleam to pierce through their helicopter. The helicopter once again sustains damage, prompting Matori to retreat.
Meanwhile, in Poipole's world, the Ultra Guardians recover as Dusk Mane Necrozma roars and charges toward the Ultra Guardians, but Lunala tackles it out of the way. Everyone then send out their pokemon to help out.
Ash:Rowlet use razor leaf, Lycanroc use stone edge and, Pikachu use thunderbolt Torrocat use ember!
Kiawe:Marowak use shadow bone and Turtonator use flamethrower!
Gladion:Lycanroc use stone edge, Silvally use air slash and Umbreon dark pulse!
Sophocles:Togdemaru zigzap and Charjabug discharge!
Lana:Popplio use bubblebeam!
Lillie:Snowy use powder snow!
Mallow:Steenee use magical leaf!
Y/b:Regirock zap canon, Archie and Stakataka rock slide, Lycanroc stone edge and Minior ancient power!
The attacks collided as a huge dust cloud forms. Back in Alola, Tapu Koko begins sending energy into the Ultra Wormhole as Lusamine and Professor Burnet in the base wonder what it's doing, then Wicke reports that they have regained communications with the Ultra Guardians. Back in Poipole's world, the Ultra Guardians are contacted by the Aether Foundation staff. The Ultra Guardians report that they're in Poipole's world and that they've discovered UB Black is the "Blinding One" who lost its light, confirming Burnet's discovery. The Ultra Guardians further report back with the "Blinding One's" true name and reveal that their attempt to restore Necrozma with their Z-Power had failed, they also report the attacks Lana they just ordered failed as well. Burnet figures that they need more power and reveals more about the mural; it wasn't just Solgaleo and Lunala that shared their light with the "Blinding One", the people and Pokémon of Alola also shared their light with it. As Sophocles wonders how to do it, Burnet sees what Tapu Koko is doing and figures they have to do what it's doing. The Ultra Guardians and their Pokémon all make Tapu Koko's pose and Lusamine sends the island kahunas a message to ask for their help.
Hala, Olivia, and Nanu get the word and ask for help from the people gathered with them to send their power to the "Blinding One". The Guardian deities, island kahunas, Lusamine, Wicke, and Burnet send their power through the Ultra Wormhole, making Dusk Mane Necrozma back away from Lunala. As the Ultra Guardians send their own power, Poipole gets its hive to join in sending power. Back in Alola, the people and Pokémon pitch in and more power goes through the Ultra Wormhole. Team Rocket sees this and as they watch, they feel their balloon shaking and see Bewear grabbing onto it, which causes the balloon to crash.Bewear sends her power into the Ultra Wormhole as well, and at its request, Jessie and James sends out Mimikyu and Mareanie to join them. As all of Alola's power makes it through the Ultra Wormhole, Lunala adds in some of its own. Necrozma receives the power and glows as it separates from Nebby, who collapses. Necrozma reassembles itself, but it is enraged and charges towards the Ultra Guardians, firing another Prismatic Laser.
Y/n:Regirock! Protect!
Regirock is just able to hold back the attack before his shield cracks and he is taken out. Back in Alola, the island kahunas use their Z-Moves to send Z-Power into the Ultra Wormhole. Back with Necrozma, it creeps up towards the Ultra Guardians, when it receives the Z-Power and turns its attention to Nebby and Lunala. Gladion boards Silvally and has it fire Air Slash to distract Necrozma from Nebby and Lunala. Lunala calls out to Gladion and throws him a Lunalium Z. Mallow and Ash run to Nebby's side and feed it a Sitrus Berry, allowing it to recover. At Gladion's request, Ash equips his Z-Power Ring with his Solganium Z and asks Nebby to lend him its power again. Naganadel then speaks to Y/n.
Naganadel:Join them. Stakataka's z move is called ultra wormhole rift and the pose is the same for the steel type z move.
Y/n:Alright. You ready Stakataka!
Stakataka:Let's go!
The three most powerful trainers present stand ready to fight. They then begin their attacks.
Y/n:Titan of space and unnatural power hear my order and lend me your power!
Ash:Searing sunraze smash!
Gladion:Menacing moonraze Maelstrom!
Y/n:Ultra wormhole rift!
The attacks all connect(I'll explain what the ultra beast z move looks like in a later chapter) Necrozma's body changes from black to shining gold as the parts split up and reassemble, held together by light in a draconic appearance; Necrozma is finally restored to its original form. The Ultra Guardians all gaze in awe of Ultra Necrozma and report the mission's success to Lusamine, Burnet, and Wicke as the eclipse in Alola comes to an end. Ultra Necrozma then uses its power to restore the world, bringing light back into it and revitalizing the floral life. The Ultra Guardians marvel at the restored state of the world as Poipole dances happily. Then, a call from Burnet alerts the Ultra Guardians that the Ultra Wormhole is about to close. However, Poipole decides to remain behind, wanting to help protect its world. Ash shares a tearful goodbye with Poipole before leaving. Poipole holds back its tears and starts drawing an image on the sand, which is revealed to be an image of Ash and Pikachu's faces with thunderbolt shapes next to them. Mallow states that Poipole is saying "Like, Like, Love" to them and Ash says it right back to Poipole as the Ultra Guardians wave goodbye before they go through the Ultra Wormhole and arrive back in Alola. Team Rocket see it as their chance to capture Nebby and Lunala, but Bewear carries them away before they can. Then, Ultra Necrozma appears as a golden light in Alola's sky for all to see before slowly dissipating.
Sometime later at the Pokemon school Kukui has his coat buttoned up and greets the class lazily with a depressing aura. The class is fearful that the Ultra Aura drain might have happened again, but Kukui replies that it's just a cold, much to the class's shock. Ash decides to do the greeting again and the class, with everything they have, loudly shouts, "Alola!"
This was something that none of them would forget.