Rayler first appears as a wild Luxio in Extreme Luxio, where he was a member of a pack of wild Luxio and Shinx. However his claws were broken and because of it, Luxio could not communicate with his pack members, causing them to shun him. In a desperate attempt to get them to acknowledge him, he kidnapped Platinum and her Piplup so that he could challenge Pearl and Diamond. He first fought Diamond's Lax and Tru and easily beat them due to their slow speed. After beating them his pack still refused to accept him and he began to attack Pearl's team. During his fight against them Pearl noticed his broken claws and quickly came up with a way for him to communicate with his pack, using his comedy Duo act as the base. Being able to communicate with his pack again, he thanked the group and left.
He returns once again in Maddening Magby, where he encountered Pearl at the Fuego Ironworks on his adventure to protect Lake Valor from Team Galactic, where he was revealed to have become the leader of the pack. As Pearl was about to enter Luxray dragged him over to a different opening and entered with him, using his X-ray vision to find the trapped Mr. Fuego. After finding him Pearl accidentally steps on a conveyor belt heading straight to a furnace. Luxray quickly jumps into action and saved Pearl, getting his back burned in the process. Pearl then asks Luxray to carry him to Mr. Fuego due to his ability to see all the conveyor belts, to which Luxray accepts. The two are soon spotted by a Houndoom who chases them throughout the building. While fleeing Pearl tells Luxray when to dodge as he focuses on their destination, though he is hit in the process. Once they arrived Luxray turned around and retaliated with Shock Wave, knocking Houndoom out. After leaving he decided to join Pearl on his journey, becoming his third Pokémon.
Rayler and Pearl
In Outwitting Octillery, Rayler works alongside his team to reach the middle of Lake Valor in an attempt to find Azelf. Halfway across the lake, they get attacked by Saturn's Octillery, who uses Octazooka to destroy their raft. Saturn shows up on a UFO-like vessel and grabs Pearl, demanding to know why he was heading for the island at the middle of the lake while Rayler, Chatler, and Chimler desperately try to free him. A few minutes later, the Galactic Bomb goes off, with its target revealed to be Lake Valor. Pearl and Saturn witness Azelf reveal itself and Saturn and his grunts begin trying to capture it. Pearl and his team attempt to stop them, but they are overwhelmed by the number of opponents and defeated.
Rayler is a proud and noble Pokémon and is very dedicated to his pack. He is stoic, serious, focused, and has a high level of commitment, refusing to back out of something he has started. He cares greatly for others and will jump straight into danger without a second thought in order to save someone.