Zexion, is a manipulator appearing in Chain of Memories. He is also known as the "Cloaked Schemer". Zexion's original self was Ansem the Wise's youngest lab assistant, and named Ienzo. He convinced Ansem the Wise that they should build an underground lab for research. He is voiced by Akira Ishida in Kingdom Hearts Re:Chain of Memories. Zexion uses his power of illusion, used to mimic others' weapons, disguise himself as others, and create duplicates of himself. His unique weapon is a lexicon. Before Kingdom Hearts II Final Mix, Zexion's weapon and powers were unknown because he had died without fighting. Because Nomura was unsure if it would be revealed later, he kept information about it secret. The development team also destroyed his gravestone in the World That Never Was that would have shown his weapon.
Zexion is one of two Organization members who appear only in Riku's story in Chain of Memories. Zexion tracks Riku's actions until Vexen's death; Zexion and Lexaeus then decide to use Riku to counter Marluxia's plan to use Sora. After Marluxia is killed, Zexion sees Riku as unnecessary and attempts to destroy Riku himself. He leads Riku into a manifestation of Destiny Islands, Riku's home. There, Zexion tells Riku about how he threw away his friends and his home and opened the door to darkness, thus destroying the islands. Following Riku's battle with a large Heartless, Zexion disguises himself as Sora and attacks Riku, telling him that he's become a pawn of the darkness. He engulfs Riku in light, but a vision of Kairi convinces Riku to accept darkness and light. With newfound confidence, Riku follows Zexion's scent through the light and causes Zexion to flee. Axel brings the Riku Replica to Zexion and convinces the replica that he can become "real" by gaining power that the real Riku does not have. The replica agrees, and as per Axel's suggestion, kills Zexion.