A resident of Destiny Islands and best friend of Sora, Riku inherited the power of the Keyblade from Terra, a Keyblade-wielder visiting the Islands. As he grew older, Riku began to long for a way off his homeworld, and a way to visit other worlds. To accomplish this goal, he, Sora, and their friend Kairi set about building a raft with which they hoped to sail to other worlds. However, before they could set out, their world was attacked by the demonic Heartless, who consumed the world. Riku was swallowed up by the darkness seconds before he was supposed to gain the power of the Keyblade, and it went to Sora in his stead.
Transported to the refugee world of Traverse Town, Riku was excited to finally see another world. Soon, he came across Sora, who had been fighting against the Heartless with the aid of Donald Duck and Goofy. It wasn't long before Riku discovered that Kairi had gone missing during the destruction of their world, and Sora had been searching many worlds to find her and Riku. Sora offered for Riku to accompany them on their journey, but Donald refused to let him. Riku left before the argument could be settled.
The evil sorceress Maleficent, who was using the Heartless for her own ends, came across Riku at this point, fostering feelings of rejection and hatred within him. Riku allied with her when she told him she would help him find Kairi, who Riku had feelings for. Soon, however, Riku found out that Kairi had apparently lost her heart, and he fell in further with Maleficent in an effort to reclaim it. He was given control over the darkness, clashed several times with Sora, and ultimately was possessed by the spirit of "Ansem", creator of the Heartless.
Sora eventually slew Ansem, and Riku redeemed himself by helping to close the doors to Kingdom Hearts, preventing a massive invasion of Heartless into the Realm of Light. He was trapped behind the doors, and eventually came to Castle Oblivion, where he clashed with the fiendish Organization XIII, as well as fighting the lingering effects of Ansem's possession. Initially trying to resist the darkness inside him, Riku eventually learned to accept a balance between the darkness and light.
Riku came to become an agent of the enigmatic DiZ, capturing the Organization member Roxas to help Sora, who had lost his memory in Castle Oblivion. Riku once again fell prey to the darkness, and was changed into a doppelganger of Ansem, but was ultimately restored, and helped Sora destroy the Organization once and for all.
Battle vs. Illidan Stormrage (by CuchulainSetanta)Edit
Riku is making his way to the summit of the Black Temple, having fought his way through many of Illidan's minions. Stepping out, he sees the Lord of Outland with his back to him, crouched over while looking over the Skull of Gul'dan. Illidan glances behind him and sees the young warrior, who gets into his fighting stance. Illidan gets to feet, tosses the Skull aside, and unveils the Twin Blades of Azzinoth. He then spreads his wings and leaps over to Riku.
Riku brings up Way to the Dawn, blocking Illidan's strike. Illidan unleashes several more strikes, which Riku struggles to block in time. Gathering his inner darkness, Riku fires a dark fireball at Illidan, who is caught off guard, being blasted backwards. Riku rushes in to take advantage of the night elf/demon's weakness, but Illidan recovers, spinning backwards and cutting Riku on the shoulder.
Riku rolls out of the way of another strike, grabbing his shoulder in pain. Illidan takes to the air again, this time unleashing a rain of fel fire. Riku jumps out of the way just in time, and turns...just in time to see Illidan swooping in with his blades. Riku starts to bring up his Keyblade, but is too late. Illidan stabs him directly through the heart with both blades, then, in one swift motion, pulls them out and decapitates Riku. Illidan cleans the blood off his blades, saying to himself "They are never prepared..."
Winner: Illidan Stormrage
Riku is a skilled combatant, but he has only been fighting for about two years. Illidan, on the other hand, has the advantage of over ten thousand years of combat experience. This, along with his ability to fly, made him the victor.