Eusine/Manga/PA/History/GSC

Eusine is first mentioned by Morty in Misdreavus Misgivings. Morty states that Eusine asked him to use his clairvoyance to search for the Legendary Pokémon. Due to Suicune's Legendary status, Morty was unable to locate where it slept. After facing and losing to Suicune in battle, Morty calls Eusine to tell him about the encounter.

Eusine physically debuts in Jumping Jumpluff, where he meets, another person searching for Suicune. After they introduce themselves to each other, Eusine deems Crystal his rival for their similar goal and proceeds to leave. He accidentally ends up crashing into a barn at the Moomoo Farm, angering the farmhands, who demand that Eusine leave and pay for the damages. By tricking the farmhands by healing their with what he claims to be "magic", Eusine gets out of having to pay for the broken roof and earns himself free milk in the process. He is immediately approached by Crystal, who saw through the trick and knew that Eusine used a Berry to heal the Miltank. Eusine assumes Crystal had followed him to get a chance at getting close to Suicune, but she states that it was pure coincidence, as she is tracking Suicune with her Pokédex.

Soon after, Suicune appears and attacks the two. Crystal deduces that the Suicune who attacked them is a fake and uncovers its true identity, a sent to throw them off from the real Suicune's whereabouts. They realize that if someone sent a diversion, the real Suicune must currently be pursued by whoever sent the Ditto. Crystal and Eusine make their way to find Suicune by using Crystal's Pokédex to track its location. Upon spotting the people after Suicune, Eusine leaves Crystal to face the pursuers in battle. He tells Crystal to go after Suicune, who is heading to Ecruteak City. Eusine finds out the pursuers are the Team Rocket Elite Trio and faces them in battle. Eusine succeeds in defeating the trio and steals the Clear Bell they had in their possession. Eusine heads to the Bell Tower, where Crystal is facing Suicune in battle. He arrives just as Crystal had been defeated and blocked from accessing the tower due to Suicune's Crystal Wall. With the Clear Bell, Eusine bypasses the Crystal Wall and heads up the Bell Tower in hopes that Suicune is still there, only to find it already gone. After Crystal wakes up, Eusine realizes that Suicune was heading to the Bell Tower to meets its master,. Eusine then leaves Crystal to continue his journey to capture Suicune. During the final battle against the Masked Man, Eusine arrives to rescue Misty and an injured Suicune from being trapped in the Crystal Wall. Due to Misty's injuries, she tells Suicune that it will have to continue the battle against the Masked Man with a new partner. Although Eusine hoped to be chosen, he is disappointed when Suicune chooses Crystal as its new partner. Later, Eusine meets up with Morty, who asks if he is disappointed that he wasn't chosen by Suicune. Eusine confidently states that Suicune will choose him one day, as he did save its life.