A long time ago, two Koraidon were brought to Paldea by Professor Sada's time machine. However, the second specimen was incredibly aggressive and attacked the first one, severely injuring it and causing it to flee, flying out from the Great Crater of Paldea before crash landing on a beach below Poco Path. After awakening, a group of Houndour led by a Houndoom living in Inlet Grotto started to harass Koraidon. Though Koraidon tried to scare them off by roaring, this only caused the Houndor to attack the player instead, forcing Koraidon to grab them and escape.
Personality and characteristics
Koraidon showed a meek and gentle personality. Though initial wary, it bonded with the player and accompanied them during their journey throughout the Paldea region. Koraidon shows compassion towards Arven's Mabosstiff and curiosity towards Penny, despite the former's initial distaste of it and the latter's shyness. Throughout the journey, it slowly regains its strength, allowing Koraidon to utilize additional forms to help the player navigate Paldea's terrain. Prior to entering Area Zero, Koraidon was still hesitant about entering due to its previous encounter with the other Koraidon. However, with the support of the player and their various friends, Koraidon joined them as they ventured into the crater, later helping protect the group from the other Koraidon.
During the Path of Legends quest, Koraidon developed a taste for Herba Mysticasandwiches, much to Arven's initial perplexity.
In Pokémon Scarlet, Koraidon can assume a series of builds which can be used for travel. By pressing +, the player can enter and use Koraidon's Sprinting Build. In this Build, the player can ride on Koraidon, replacing the bike and Ride Pokémon from previous games.
At first, Koraidon can only be ridden in its Sprinting Build and given the option to jump while pressing B, as well as the ability to swim in water through its Swimming Build, replacing the SurfHM from previous games. However, Koraidon can only swim inside settlements without the swimming upgrade. Koraidon will be given an upgrade after each Titan Pokémon the player defeats:
Defeating the Stony Cliff Titan grants Koraidon the ability to dash, giving Koraidon a higher speed option when pressing the left stick.
Defeating the Open Sky Titan grants Koraidon the ability to swim better while in its Swimming Build.
Defeating the Lurking Steel Titan grants Koraidon the ability to jump higher.
Defeating the Quaking Earth Titan grants Koraidon the full ability to use its Gliding Build. Working similarly to Braviary, pressing B while in the air gives Koraidon the ability to fall slower and travel in the air for a short time before dropping.
Defeating the False Dragon Titan grants Koraidon the ability to climb. Similar to Sneasler, by jumping and touching a wall, Koraidon can attach itself to said wall if the player presses B, allowing Koraidon to escalate the wall in all directions. Pressing the B button again will allow Koraidon to detached itself from the wall.
Lastly, when confronting its fellow Koraidon at the end of the game, Koraidon regains its battle confidence and reasserts its Apex Build it used at the beginning of the game, allowing the player to subsequently use it in proper battle.