Fakes should be destroyed!!Riku Replica to Sora
Riku Replica is a Replica of Riku created from the data Vexen had gathered. He appeared in Kingdom Hearts: Chain of Memories, Kingdom Hearts Re:Chain of Memories and Kingdom Hearts III, and acts as one of the main antagonists of the former game.
Though he almost always appears in Dark Mode, the only time when he did not have this suit on is his debut in either storyline. Originally a subject to test the real Riku, the Replica was later exploited to become a puppet of Marluxia who attempted to use him to manipulate Sora and overthrow the Organization.
The Replica was more aggressive and protective than Riku. A key difference between the two was as follows: while Riku feared the darkness in his heart, the Replica embraced his and wielded it effectively. He was also more stubborn, contributing to the fact that he was a persistent enemy throughout the game. Another prominent factor was his determined search to discover more about his existence. He tended to become angry when faced with confusion of any sort, in a way similar to Sora, as shown when the Organization members, and more specifically, Larxene and Vexen, deceived him.
At the end of his life, the Replica became much more like the original, turning sullen and mellow. He often lashed out at anyone who talked back to him, even if they overpowered him. He seemed to be similar in strength to Riku at the latter end of Kingdom Hearts, when the original was under the influence of Ansem, Seeker of Darkness.
The Replica seemed to possess true emotions, as he possessed a dogged determination to protect Naminé, and on occasion, outright affection for her, though his belief in it was merely part of the illusion Naminé had created by tampering with Sora's memories while at Castle Oblivion.
The Riku Replica is physically identical to Riku as he appears in Kingdom Hearts, sporting the same skin tone, bright blue eyes, and shoulder-length silver hair. He initially appears in Riku's standard outfit, but quickly shifts into his Dark Mode form, and remains in the latter outfit for the remainder of his appearance.
Chain of Memories
The Riku Replica was created by Vexen in order to test Riku's strength, and hopefully cause Riku's heart to return to the Darkness. At first Riku is shocked to see his counterpart; however, after the original heard the Riku Replica's taunts, a battle begins. Due to the short time of Riku Replica's existence, he lacked experience and is quickly defeated by the original. Riku then attempts to destroy the Replica, but fails when the Riku Replica utilizes the power of Darkness.
Riku Replica escapes, and eventually ends up in the Organization's chambers, where Larxene taunts Riku Replica over his loss. However, the replica denies any fault of this, saying that his powers had not grown enough, which results in her bashing him into the wall calling him "nothing but a mere toy". The Organization members later change their plans, hoping to turn Sora into their puppet and overthrow the Organization. Larxene suggests that Riku Replica's memories should be rewritten to be the same as the original's so he would become a much stronger and more useful tool.
Riku Replica, upon hearing Larxene's idea, rejects it, saying that he did not need his original's pitiful memories, but all the members began to agree upon Larxene's plan. Fearing that he would lose his memory, Riku Replica assaulted Larxene. However, he is quickly knocked out and Naminé is ordered to rewrite the replica's memory.
After having his memory rewritten, Riku Replica swore to protect Naminé, and saw Sora as a threat, feeling already betrayed by him as he thought Sora didn't care for him and cared only for Kairi. Sora's first encounter with the replica confuses the Keyblade wielder. Sora manages to defeat the replica, who then escapes. Riku Replica later encounters Sora in Castle Oblivion's 8th floor, where he urges Sora to leave, as he would protect Naminé. Hoping to regain his friend, Sora offers to jog Riku Replica's memory, but nothing works, and a fight ensues.
Riku Replica, defeated, felt even more anger when Sora offers his help so they could protect Naminé together. Hearing Sora say "together", Riku Replica is filled with sadness and rage and he screams his true feelings at Sora, telling him that he was always trying to worm his way into his heart and that it never mattered to him how he felt. After that, Riku Replica runs away, leaving Sora behind, confused.
Around this point, Vexen loses control of the Riku Replica, allowing it to go missing within the castle. The replica's disappearance allows Axel and Larxene to mock Vexen for his experiment's seeming failure, and for Marluxia to threaten Vexen into fighting Sora himself. However, Young Xehanort arrives around this time, unknown to the inhabitants of the castle, and collects the heart of the Riku Replica, taking it to the future and gifting him a new replica body under the identity of Dark Riku, who would become a member of the real Organization XIII. After Dark Riku's defeat at the Keyblade Graveyard, his heart returns back to his original replica body in Castle Oblivion in the past with no memory of the future.
Riku Replica's third encounter with Sora happens on the 11th floor, after his creator's demise, where he means to force Sora to leave. Sora, who has defeated Vexen, tells his friend that he is free, but the Riku Replica claims that he was protecting Naminé from him, of his own free will. Riku Replica then tells Sora of the very same promise Sora made to Naminé when they were young. Sora claims that he was the one who made the promise and shows Riku Replica the lucky charm Naminé gave him as proof. In a rage, Riku Replica lashes out at Sora, and tells him that the Keyblade master's lucky charm was a fake, and the lucky charm he holds is the real thing. Sora and the replica fight, but the Riku Replica is once again defeated, and runs away. He even drops his charm, which turned into a World Card.
Riku Replica's false memories come to an end on the 12th floor of Castle Oblivion. Meeting again with Sora, he insists that he is the one destined to protect Naminé but Sora's wrecked memories keep interfering. Sora defeats the replica again, however, and when Sora goes to help him, the Replica retaliates, knocking Sora back.
Just as Riku Replica is about to deliver the coup de grâce, a desperate Naminé shatters Riku Replica's false memories and his heart with them. Larxene later interferes, and explains Riku Replica's nature and creation (note that until this was revealed, Sora believed the Riku Replica to be "the real Riku"). An angered Sora fights with the Organization member, successfully defeating her.
Riku Replica is last seen in the top floor of Castle Oblivion, where he saves Naminé from Marluxia. Despite losing his memory, he remembers his oath to protect Naminé. He protects her throughout the battle between Sora and Marluxia. In the end, he leaves Sora and Naminé, saying a fake like him does not deserve to be together with them; Sora, however, comforts the replica. Feeling Sora's warm kindness, the replica smiles and leaves. He still has one more thing to do: defeat the real Riku.
After leaving Sora, Riku Replica joined Axel, who would use him for enacting his (and Saïx's) own plans. They seek out the wounded Zexion, who is initially shocked to see them, believing Axel to be accompanied by "the real Riku". His relief does not last long, however, after Axel presents the replica with an idea, telling that if he gains power that the real Riku doesn't have, he could be something real, not someone's counterpart. Agreeing, Riku Replica approaches Zexion, and drains the life force out of him (initially giving him Zexion's powers).
Riku Replica is later seen in a memory version of Twilight Town, where he meets Riku in front of the old mansion. The replica remarks that Riku no longer feared the Darkness, in which he earns the original's confusion in return. Riku Replica replies that he is Riku, and thus he would know everything about his counterpart. Feeling annoyed, Riku remarks that he is himself, and no one could possibly be him. Angered because of the fact that he is "a fake", the Riku Replica taps his Dark powers, and states that in the end, he was still nothing but a replica, even after gaining new power.
Blinded by jealousy and rage, Riku Replica engages the original, and the two have a fierce battle. In the end, despite Riku Replica's new found powers, he is defeated, and slowly fades back into the Darkness. With his dying breath, he asks Riku where a replica's heart like his would go. Riku comforts the replica, stating that it would go to the same place as his. The replica smiles, and remarks "A faithful replica until the very end. That's... okay", before fading back into the Darkness.
Kingdom Hearts III
It is discovered that after his defeat, Riku Replica's heart ended up in the Realm of Darkness, where he wandered until Riku and Mickey's battle with a Demon Tower, when Riku was captured by it, he was helped by Riku Replica, who talked to him. Before leaving the Realm of Darkness, Riku left his damaged Way to the Dawn Keyblade behind for the Riku Replica. After Anti-Aqua's appearance before Riku in the Realm of Darkness, Riku Replica appears to Riku, wielding the repaired Way to the Dawn, and joins with him. After returning to Destiny Islands, Riku converses with the Riku Replica, who laments that he failed to make anything of himself, and after Sora and Riku moved on, his mind and body fell to the darkness. He tells Riku that he would rather see his end with him than in darkness, and that he had one last thing to see through.
The Replica is seen again in the Skein of Severance during the Keyblade War. After Sora and Riku defeat Dark Riku, it is revealed to Riku that Dark Riku is the Riku Replica from the past - during the time when he believed he was the real Riku. The present day Riku Replica emerges from Riku and separates the Dark Riku from the Replica body he was inhabiting, with the intention of leaving the Replica body for Naminé. He and his dark self then disappear.
The Riku Replica fights with the same style as the real Riku, but his sleights use different requirements than Riku's sleights. For example, Riku can only use Dark Aura with three 9's, a total of 27. However, the Replica can use any three cards, granted the right types of cards are used, such as 4, 7, and 8, to perform Dark Aura. He never uses the Dark Break Sleight. Instead he substitutes it for a sleight called "Helm Split".
The Riku Replica is also more aggressive, which leads to some open moments during his battles.