Eyan could be seen standing outside of the Elm Pokémon Laboratory in New Bark Town, peering inside from the west end of the building. Emile approached him, but Eyan angrily shoved him away.
Offscreen, Eyan stole Professor Elm's Level 5 male Chikorita.
Eyan, going by ??? at the time, met Emile at the exit of Cherrygrove City. He insulted Emile by saying it was a waste to give a wimp like him a Pokémon from the Lab, and challenged him to a battle, matching his Chikorita against Emile's Level 7 Totodile, Odairu. With inferior Attack, Defense, and HP, Chikorita could deal little damage to Odairu with his Tackle. Odairu, in turn, used Rage to defeat Chikorita in just three attacks. Eyan barely acknowledged the loss before giving his name and stating that he would become the greatest Trainer. He departed toward Route 30, and Emile later mentioned his name to the police officer in the Lab.
Emile referenced Eyan when he started talking similarly to him, talking about strong and weak Pokémon.
Emile encountered Eyan at the top of Sprout Tower, where he had easily defeated Sage Li and earned the Flash HM. Li complimented his skills as a trainer but warned him that he should treat his Pokémon better than the harshness that he displayed. Eyan then noticed Emile, and groused to him about the Elder's weakness, saying that he, Eyan, only cared about strong Pokémon before using an Escape Rope to leave.
Offscreen, Eyan caught a Gastly and a Zubat, and his Chikorita evolved into Bayleef.
Eyan confronted Emile as he attempted to leave Azalea Town after defeating Bugsy, talking to him about Team Rocket's return. He expressed skepticism when Emile claimed to have beaten them, and then challenged him when Emile said he wasn't joking. Both trainers had three Pokémon on their team for this battle.
Eyan sent out his Gastly first, which battled against Odairu. The Ghost-Type's Lick attacks did little damage and failed to paralyze the Totodile, and after missing with Hypnosis, Gastly fainted to Odairu's third Water Gun attack.
Eyan then sent out his Bayleef, his strongest Pokémon, which battled against Emile's Growlithe, Roary (nicknamed GRWLTH at the time), which was at the same Level. Bayleef attempted to use Poisonpowder first, but missed, and lost a chunk of its health to Roary's Ember. It dealt little damage with its Razor Leaf attack and then fainted to a critical Ember that wiped out its HP.
Eyan then sent out his Zubat against Roary. It used Bite twice, taking out almost a quarter of the Growlithe's HP, but Zubat fainted to the fire-type Pokemon's third Ember attack.
Upon his defeat, Eyan showed his disgust for his team's weakness, blaming that for his loss. He then expressed his hatred for Team Rocket's weakness and cowardice. He called Emile a weakling as well and warned him to stay out of his way, and then stormed past him into Ilex Forest.
Offscreen, Eyan caught a Magnemite, and his Gastly evolved into Haunter.
While exploring Ecruteak City's Burned Tower, Emile again encountered Eyan, who had come looking for the Legendary Pokémon that was supposed to roost there. His frustration at finding nothing there led him to challenge Emile, nonsensically accusing it of being his fault. Both trainers had four Pokémon on their team for this battle.
Eyan sent out his Haunter first, which battled against Emile's Phanpy, Darmani. Haunter used Curse against Darmani, which opened the way for the Phanpy to defeat it with two Mud-Slap attacks.
Eyan then sent out his Bayleef, his strongest Pokémon, which once again battled Emile's Growlithe, Roary. Bayleef used only Razor Leaf, and though the assault took out most of Roary's HP, the Fire-type's repeated Ember attacks depleted Bayleef's faster, and it fainted.
Eyan then sent out his Zubat, which battled Darmani. Zubat's depleted the weakened Phanpy's HP quickly with repeated Bite attacks, taking comparatively little damage to the Ground-type Pokemon's Tackles. However, before Zubat could deal the final blow, Darmani used Flail, which wiped out Zubat's remaining HP.
Eyan then sent out his Magnemite against Darmani. With a damage multiplier of x6, Darmani's Mud-Slap nearly knocked the Electric/Steel-Type out, but it survived and knocked out Darmani with a Sonicboom attack. However, the battle ended when Emile sent Roary out again, and a single Ember attack knocked Magnemite out.
Upon his defeat, Eyan groused about there being no challenge in battling wimps, which Emile agreed with: "Case in point: I won." Eyan dismissed that and insultingly said that Emile could never catch a Legendary Pokémon anyway. The ground then collapsed beneath Emile, and he dropped to the basement. Eyan consequently insulted Emile's intelligence at falling into a hole.
Eyan next appeared in Olivine City, emerging from the Olivine Gym as Emile entered the city. He stated that he had no interest in battling a wimp like Emile, and complained about the city's Gym Leader, who was taking care of a sick Pokémon at the Lighthouse. Eyan expressed his opinion on the situation, believing that any Pokémon that couldn't battle was worthless. He suggested that Emile train at the Lighthouse, thinking it could potentially make him less weak. Eyan then left the city, and Emile wondered aloud why he stepped aside to let Eyan past instead of forcing Eyan to shove him aside.
Eyan appeared again in the Rocket Hideout in Mahogany Town as Emile was about to enter Rocket Executive Petrol's room. He told Emile that he had planned to destroy Team Rocket, and then asked who the guy in the cape who used Dragon Pokémon was, having lost in a battle to him. Eyan didn't care that he lost, again attributing it to his Pokémon's weakness, but expressed fury at losing to someone who believed that he needed to love and trust his Pokémon more. He then told Emile that he didn't have time for him, and shoved him before running off.
Offscreen, Eyan caught a Sneasel, and his Zubat and Bayleef evolved into Golbat and Meganium.
Later, Lance expressed some concern about the young man he battled in the hideout.
Eyan later confronted Emile in the Goldenrod Underground, having tailed him there. He told Emile that he didn't need him underfoot while he, Eyan, took care of Team Rocket. He then recalled that Emile beat him before, and said it was a fluke before stating that he repaid his debts, and challenging him. Both trainers had five Pokémon on their team for this battle.
He sent out his Golbat first, which battled against Darmani, who had evolved into Donphan. Golbat immediately used Confuse Ray, which caused the Donphan to hurt himself in confusion, and then used Bite as Emile healed Darmani with a Full Heal. Then he used Confuse Ray again, and the pattern repeated. Emile then attempted to use Rollout while Golbat continues with Bite attacks, and the Donphan only attacked once before Bite made him flinch. Emile grudgingly used a Hyper Potion to heal Darmani to full health, while Golbat used Bite again. He then used another Confuse Ray before resuming Biting, Darmani proving unable to break through the confusion and hurting himself twice in a row. He then snapped out of it, however, and used another Rollout, this one a critical hit that nearly knocked Golbat out. The Poison/Flying-Type managed to break the combo with another Bite, making the Donphan flinch and taking advantage of it to reduce him to a mere sliver of health. But Golbat proved to be too weak to dodge Darmani's next Rollout, and it fainted.
Eyan then sent out his Meganium, his strongest Pokémon, which immediately finished off Darmani with Razor Leaf. Emile then sent out his Shiny Koffing, Methane. While Methane used Sludge, Meganium used Reflect and then Body Slam, paralyzing the Koffing and preventing its attack that turn. Methane then began using repeated Sludge attacks while Meganium used repeated Body Slam attacks, both Pokémon quickly growing weak as a result. When Methane's Sludge poisoned Meganium, Emile healed his Pokémon with a Super Potion, and Meganium was only able to deplete half of the Koffing's restored HP before the poison overtook it, and it fainted.
Eyan then sent out his Magnemite, which battled against Roary. Magnemite attempted to use Thunder Wave but missed due to Roary using Dig, which knocked it out immediately upon impact.
Eyan then sent out his Haunter against Roary. Haunter used Shadow Ball, taking out almost a third of Roary's HP before the Growlithe went underground again. Haunter's Curse attack failed while Roary was underground, and the Ghost/Poison-Type lost most of his HP to Dig. Roary lost another chunk of HP to another Shadow Ball, but then he used Dig once again, dodging another Shadow Ball before finishing the Ghost-type off.
Eyan then sent out his Sneasel against Roary. Despite the Type disadvantage, Sneasel easily endured an Ember attack before knocking Roary out with two Faint Attacks. But the battle ended when Emile sent out Odairu, who had evolved into a Feraligatr, and he wiped out Sneasel's remaining HP with a single Surf attack.
Upon his defeat, Eyan wondered why he had lost, when he had assembled a strong team and not held back. He considered Lance's words, thinking that maybe love and trust were what he was missing. He then stated his resolve not to let his defeat stop him from becoming the world's most powerful trainer, and then left.
Offscreen, Eyan caught an Abra and trained it enough that it evolved into Kadabra, and his Magnemite evolved into Magneton.
At the end of Victory Road, Eyan confronted Emile once more. He belittled Emile for considering taking the Pokémon League challenge, calling him much weaker than himself. Eyan asserted that he was not like he was before, and had assembled the best and strongest Pokémon, before once again challenging Emile. He had six Pokémon on his team for this battle, while Emile had only four.
Eyan sent out his Sneasel first, which battled against Darmani. Sneasel attempted to use Fury Cutter, but the first attack missed and the second did barely any damage. Darmani, meanwhile, used Rollout, depleting Sneasel's HP with just two strikes.
Eyan then sent out his Meganium, his strongest Pokémon, against Darmani. Though Meganium's first Razor Leaf failed to knock Darmani out, the Grass-Type endured the third stage Rollout with relative ease and finished Darmani with a second Razor Leaf, this one a critical hit. Emile then sent out Methane, who had evolved into Weezing. Meganium endured the Poison-Type's Sludge Bomb by using Reflect, and retaliated with Body Slam, but failed to paralyze him, and subsequently fainted to his second Sludge Bomb.
Eyan then sent out his Kadabra, to which Emile sent out Odairu. A single critical Slash attack knocked Kadabra out before it could launch a single attack.
Eyan then sent out his Magneton against Odairu. The attempt to use type advantage failed when Odairu used Earthquake, knocking Magneton out in one hit despite Meganium's lingering Reflect.
Eyan then sent out his Golbat against Odairu. The Feraligatr used Ice Punch, but Golbat survived the attack and used Wing Attack in response. It did little damage to the Water-Type, however, and another Ice Punch knocked Golbat out.
Eyan then sent out his Haunter, his last Pokémon, but it too fell easily to Odairu, losing all of its HP to a single Earthquake.
Upon his defeat, Eyan reflected that he was starting to understand what Lance had told him about what he lacked. He reiterated that he still planned on becoming the greatest trainer, and would find out why he couldn't win and become stronger. He vowed to find Emile after that and beat him with all his power, and snapped at him to keep at it until then before leaving.
Offscreen, his Haunter and Kadabra evolved into Gengar and Alakazam.
A much more mellow and mature Eyan confronted Emile in Mt. Moon. After remarking on how long it had been, he said that since he lost to Emile, he and his Pokémon had pondered over what they lacked, and had come up with an answer. He declared that he'd show it to Emile, and challenged him. Both trainers had full teams of six Pokémon for this battle.
Eyan sent out his Sneasel first, which battled against Roary, who had evolved into Arcanine. The Fire-Type knocked Sneasel out with a single Flame Wheel attack.
Eyan then sent out his Golbat against Roary. The Fire-Type attempted to use Iron Tail, but Golbat dodged before responding with Wing Attack. Roary's second Iron Tail struck, wiping out more than half of Golbat's HP, and it retaliated with Confuse Ray. The subsequent damage from confusion combined with repeated Wing Attacks nearly knocked Roary out, but the Arcanine managed to strike Golbat with another Iron Tail, knocking it out.
Eyan then sent out his Gengar, which battled against Darmani. The shadowy Pokémon used Curse first, which left it open to be knocked out by a critical Mud-Slap.
Eyan then sent out his Meganium, his strongest Pokémon, which battled Roary. The speedy Fire-Type wiped out half of Meganium's HP with Flame Wheel, and its retaliatory Poisonpowder missed, leaving Roary free to knock it out with another Flame Wheel.
Eyan then sent out his Alakazam, which immediately fainted to a critical Shadow Ball from Emile's Espeon, Vui.
Eyan then sent out his Magneton, only for Emile to send out Methane and order him to use Explosion. Despite the type disadvantage, the blast knocked Magneton out, ending the battle.
Upon his defeat, Eyan admitted that he hadn't trained his Pokémon as well as he thought, and admitted defeat fair and square. But he swore to Emile that it wasn't over, vowing to become the best Pokémon trainer...because he had his team behind him. He promised Emile that he would one day prove his strength by defeating him, and then departed, not to be seen again in the LP.
Canonically, the rival's name is Silver, but the game's customization gave Emile the option to name him whatever he chose. He gave him the name Eyan after SuperSkarmory, who had named his own rival Emile.
As of his most recent appearance, his team was as follows:
- Sneasel (Lvl. 41)
- Golbat (Lvl. 42)
- Magneton (Lvl 41)
- Gengar (Lvl. 43)
- Alakazam (Lvl. 43)
- Meganium (Lvl. 45)