Gladion/Manga

In the Pokémon Adventures manga
Gladion debuts in The Decision and the Tournament of Six. He first appeared as a participant at an Iki Town festival tournament. Initially, he was away when the placement of the participants was being decided, but returned just when the tournament started. His reason for his absence was due to him investigating a crack in the sky his had sensed.

In The Announcement and the Prize, Gladion was paired up against Hau, the grandson of the Island Kahuna Hala. During the battle, Gladion asked Hau why he decided to join the tournament and assumed Hau wished to surpass his grandfather. When Hau replied that he joined because he thought it would be fun, Gladion berates him and calls him weak. Eventually, Hau is defeated, allowing Gladion to move to the next round.

In The Party Crasher and Guzma the Destroyer, Gladion's opponent is. Moon revealed that she also saw a crack in the sky and asks Gladion to tell her about it. Gladion agreed, but only on the condition that Moon defeats him. During their battle, Moon proved to be an effective strategist and nearly defeats Gladion's. Despite this, Porygon eventually defeats Moon's final Pokémon through luck, giving him the win.

In The Final Match and a Surprising Finale!, Gladion faces off against in the finals. Due to the immense defense Type: Null possesses because of its iron mask as well as its incredible strength, Sun struggled to defeat his opponent. After Sun's strategy to get through Type: Null's mask fails, Gladion angrily tells him to quit fooling around and begins to question Sun's motivations for participating. Angered by Gladion's attitude, Sun angrily declares that he has a goal he needs to accomplish. As he does this, the cast on Sun's arm unravels, revealing a Sparkling Stone underneath. A powerful energy shoots out from the crack in the sky and lands on the Sparkling Stone before moving towards Sun's,. The energy powers up Dollar's, allowing it to create a powerful that defeats Type: Null. The strain of the attack causes Sun to pass out as he wonders just what move it was that Dollar used.

Afterward, a defeated Gladion leaves Iki Town. Realizing that he lost his chance to meet with the tapu, Gladion decides to find a place to train himself so that he may be fully prepared to face the Ultra Beasts.

In Going Ashore and Neighboring Akala Island, he travels to the Ruins of Conflict to try and meet with, only to find Guzma there. Guzma praises Gladion's skills at the tournament and offers him a job as an Enforcer for Team Skull. To Guzma's surprise, Gladion immediately accepts, but wishes to know about the person Guzma mentioned when he left during the tournament. Guzma feigns ignorance about his earlier statement and tells Gladion to follow him to Team Skull's hideout.

In PASM11, Sun and Moon traveled to Memorial Hill, where they find a defeated Kiawe lying on the ground, unconscious. Kiawe reveals that Gladion attacked him in order to get info on the location of the Ruins of Life, where resides. In PASM12, the three travel to the ruins, where they encounter Gladion, who managed to find and easily kidnap Tapu Lele. Moon reveals that Tapu Lele must be resting from the injuries it sustained when it fought a that emerged above Lush Jungle. When asked by Moon about his intentions, Gladion reveals that he intends on capturing the guardian deities. Moon assumes Gladion must need the deities to fight off the Ultra Beasts and suggests that they work together. Sun refused to work with someone who chooses to work with villains and decides to defeat Gladion with his newly learned Z-Move.

Due to not possessing a Z-Ring yet, Sun is forced to borrow Kiawe's Z-Ring, but it is destroyed by Gladion's Type: Null before he can receive it. Gladion reveals that he was forced to forfeit the Iki Town tournament due to Hala discovering that Sun obtained a Sparkling Stone from Tapu Koko. Although Gladion claims that Sun wouldn't have won even with the Z-Move, a voice appears and points out that if Gladion truly believed that, he wouldn't have destroyed Kiawe's Z-Ring. The voice is revealed to be Kahili, who uses her Pokémon to attack Type: Null before sending Sun a Z-Ring created by Hala. Sun puts on the Z-Ring and prepares to use it to defeat Gladion.

In PASM13, the attack succeeds, causing Type: Null's mask to start breaking. Gladion, fearing what would happen if the mask shatters completely, switches out for his Porygon. Sun attempts Inferno Overdrive again, but the attack fails, leading to Dollar's defeat. Gladion decides to give up on capturing Tapu Lele, calling it too weak to help him fight the mysterious creatures. Gladion reveals that the cracks in the sky are not an opening but an exit, and that something must be trying to break free into their world. In PASM14, Gladion traveled to Po Town, Team Skull's base of operations. There, he was attacked by the Team Skull Admin, Plumeria, who wanted to see if Gladion was skilled enough to be an Enforcer. Though Gladion proves to be strong enough for the role, his negative attitude angers Plumeria to the point where she refuses to accept him as a true member of Team Skull. When Plumeria tells Gladion to follow her, Gladion complies, but is momentarily distracted when a  jumps past him.

In PASM19, Gladion appeared at Po Town, where he found Guzma using three Ultra Beasts to attack the Trial Captains and Hau. Gladion demanded that Guzma reveal who gave him the beasts as well as the he used to open an Ultra Wormhole. Guzma, annoyed at the accusation that someone is controlling him, sent out his to attack, but Gladion managed to dodge it. When Guzma asked to know why Gladion agreed to join Team Skull, he revealed that his true goal is to destroy the Ultra Beasts.

Gladion had Type: Null battle the beasts Guzma summoned, and due to its nature as a Pokémon specifically designed to fight Ultra Beasts, Type: Null was able to inflict more damage on the beasts when the Captains' Pokémon were barely able to make a scratch. Gladion revealed to everyone that Type: Null was created by the Aether Foundation and that Lusamine, the Aether Foundation's president, is just using Guzma to fuel her desire to create a paradise for herself and the Ultra Beasts she loves so much. Guzma rejected Gladion's accusation, but was captured by a before he can finish talking. Moon tried to rescue Guzma, but was stopped by a, allowing Nihilego to drag Guzma into an Ultra Wormhole. Afterward, the other Ultra Beasts escaped from Po Town's barrier, allowing them to wreak havoc on the rest of Ula'ula Island. When the Captains asked Gladion what they can do to help, he refused to answer due to them claiming that his statements on Lusamine's motives were just lies. He then states that they wouldn't be able to fight the beasts regardless and rides off on Type: Null.

Later, Gladion, Professor Kukui, Molayne, Sophocles, and Acerola fought off a and  at  to prevent them from reaching Hokulani Observatory, which was being used as a shelter for those caught up in the Ultra Beasts' rampage. While Type: Null easily defeated Celesteela, Gladion was momentarily distracted when Lillie appeared and called out to him. Taking the opportunity, Guzzlord leapt in to attack Lillie, only to be easily swatted away by Type: Null, who evolved into a while doing so. Lillie revealed that three months ago, she stole Nebby and ran away from Aether Paradise after Lusamine tried to use Nebby's power for her own goals. When Lillie revealed she also stole a Sun Flute from Lusamine, Gladion decided that they should head towards the Altar.

Gladion and Lillie later arrived on Poni Island, where they passed through Poni Wilds on their way to the Altar. As they traveled, Gladion told Lillie about the Legendary Pokémon of the sun and moon, and. He also revealed his plan on obtaining the two Pokémon and having them help him destroy the Ultra Beasts. When Lillie suggested getting Sun, Moon, and the others to help them, Gladion refused, as he believed they were too out of the loop of their family troubles to be of any use. Lillie attempted to argue against this, only to be interrupted by appearing and attacking them both. As Silvally and Xurkitree fought, Nebby flew out of Gladion's hands and into the sky, where it met with another.

After Xurkitree was defeated, Gladion and Lillie met up with Sun and Hapu. Hapu revealed that the Sun Flute is part of a pair with the Moon Flute in her possession. While Gladion was unable to get the Sun Flute to make any sounds, Sun managed to successfully play it. The four guardian deities then appeared and took Sun to the Poni Altar along with the Sun and Moon Flutes. Gladion, Lillie, and Hapu then proceeded to follow after them.

Once they arrived at their destination, Gladion and Lillie found Faba in battle with. Cornered, Faba was defeated and captured. After heading to the Altar, Gladion and the others found that Sun and Moon managed to evolve Nebby and the other Cosmoem into Lunala and Solgaleo, respectively. After Anabel explained what the two Legendary Pokémon are and their connection with Cosmog, Lillie revealed that the Aether Foundation had been abusing Nebby to force it to create wormholes. She took Nebby to save it, but was completely unaware that there was a second Cosmog the entire time. Shortly after, Anabel received a call from Looker, who reported that a large number of Ultra Beasts have made their way to Poni Island.

While Gladion, Moon, Anabel, and Hapu fought off the beasts, Sun chose to confront Faba about returning the island the Aether Foundation took from his great-grandfather. During the conversation, Faba revealed the island was given to Sun's great-grandfather from a member of the Foundation. When Gladion and Lillie heard this, they had an idea who it could be, but were interrupted by a larger than usual Ultra Wormhole appearing with a emerging from it. The hand took control of Solgaleo's body. The possessed Solgaleo grabbed Sun with its tail and jumped into the wormhole. Nebby, with Moon still on its head, activated its third eye and flew into the wormhole.

Six months after the Poni Island incident, Lusamine disappeared while Faba had managed to take control of the Aether Foundation, running it like a dictatorship. At the Aether House on Ula'ula Island, Wicke told Gladion and Lillie that Lusamine was found on Poni Island playing with a group of Ultra Beasts. Gladion suggested going to get Lusamine, but was told to stay behind as he hadn't fully recovered from the injuries he sustained from being exposed to the energy from Silvally's evolution. Wicke decided the best option was for her to return to Aether Paradise and gather information before making their next move.