This special Riolu was befriended by Kyle before moving to Almia (revealed in the Ranger Net mission Rescue Kidnapped Riolu!), and he seemed obsessed with Riolu beforehand. In the mission Rescue Kidnapped Riolu, Riolu should be saved from Team Dim Sun, as they will use it as weapon to restore them. It seems to have a connection with Kyle using Aura, since he used it to target to Team Dim Sun's hiding place when the lights went off. The Riolu is later captured by the player and can be sent to Pokémon Diamond, Pearl, or Platinum.
Diamond, Pearl, Platinum, HeartGold and SoulSilver
A Riolu can be transferred from Shadows of Almia to a Generation IV game and obtained through Mystery Gift. This male Riolu knows Aura Sphere (which, in the main series, cannot ordinarily be learned by Riolu) and has his Original Trainer registered as Kyle, the character he befriended in Shadows of Almia.
Riolu used to live in the Lucario Kingdom before it was kidnapped to be used by an evil group. While it was being tested in a lab, a different mysterious group broke into the lab and supposedly rescued Riolu. After realizing that it hadn't been rescued Riolu then escaped from the group and fled into a nearby forest where it encountered Ash, Dawn, and Brock. As Ash tried to approach Riolu it attacked him with Aura Sphere. While trying to attack Ash again Kellyn, a Pokémon Ranger, blocked it using his Vatonage Styler. Riolu tried to escape but the group pursued it. Shortly after finding it again the group are confronted by J's Henchmen attempting to steal Riolu however they are foiled by Kellyn.
To try and gain Riolu's trust Kellyn gave it a small pouch, containing a small wooden Riolu made by Riolu's carer, however Riolu was still unsure whether to trust the group or not. After Kellyn explained Riolu's situation Ash was eager to help it get back home reassuring Riolu that it could trust him. While traveling down a stream the group were attacked again, this time by a group of Sharpedo, belonging to J's Henchmen, that destroy their boat. J then appeared attempting to catch Riolu but missed and hit Riolu's pouch causing the wooden carving to float downstream. In a desperate attempt to get it back Riolu swam after it only to be caught in the current and forced underwater. Ash managed to save Riolu and returned the wooden carving to it, which made Riolu begin to trust him. While trying to escape they were spotted by J and her Henchmen and, in an attempt to catch Riolu, J's Salamence set the surrounding forest on fire.
Ash and Riolu
J then confronted Ash and succeeded in stealing Riolu, causing the wooden carving to fall to the ground at Ash's feet. After escaping the forest fire with the help of Chimchar's Dig, Ash snuck onto J's ship and attempted to rescue Riolu only to be captured and thrown out. After realizing the strong bond he shared with Riolu, Ash managed to track down Riolu along with J and her client. The client then fled with the help of his Fearow taking Riolu with him forcing Ash and Kellyn to chase him. After losing his Fearow the client escaped into a cave with multiple exits and blocked off each exit with his Aggron's Hyper Beam. Ash, sensing Riolu's aura found where the client had gone and rescued Riolu. Not willing to give up Riolu easily the client had his Aggron attack with Hyper Beam but was defeated by Riolu's Aura Sphere and Pikachu's Volt Tackle.
In the end Riolu is reunited with his carer while the client and his henchmen are arrested. Before saying goodbye Ash returns the wooden carving to Riolu who was then taken back to the Lucario Kingdom.
Personality and characteristics
Because of constantly being kidnapped by evil people, Riolu gained a fear of all people as seen as when it attacked Ash with Aura Sphere when he was trying to help Riolu heal its wounds. Overtime, however, Riolu became more comfortable being around Ash and his friends. It has a wooden statue of itself that it treasures deeply because it was made by the man it lives with, and if this wooden carving is in any danger, Riolu will stop at nothing to save it, as seen when the carving got swept away in the river and Riolu stopped at nothing to get it back, showing that Riolu can get really emotionally attached to an object that is special to it.