Zexion

Like Axel, Zexion (ゼクシオン, Zekushion?), the "Cloaked Schemer", is a skilled manipulator by nature. Appearing in Chain of Memories, his talents lie outside of battle; he is the only Organization member who does not fight in a gameplay battle and lacks a voice actor.

He is one of two Organization members who appear only in Riku's story. He has the ability to identify individuals by their scent and is able to sense when they die by noticing their scents fading, and seems to be able to do so from great distances. He can also shapeshift. His element is unknown.

Zexion informs Vexen and Lexaeus when he senses two new scents in the lowest basement of Castle Oblivion. One of the scents is Maleficent, and he senses that she is eliminated by the other visitor, one with a scent "exactly similar" to that of Xemnas (referred to as the Superior). With little information on what was happening, he and the others decide to await development. Not long after, he identifies the other guest in the castle: Riku. He observes the boy's progress through Castle Oblivion until Vexen's death, when he and Lexaeus decide that they should use Riku just as they believe Marluxia will use Sora.

After Larxene, Lexaeus, and even Marluxia are killed, Zexion sees that Riku is no longer needed and attempts to destroy Riku himself. He does not plan to use brute force, though, partly because of personal preference, and partly because Riku already defeated Lexaeus, one of the stronger Organization members. He leads Riku into a manifestation of Destiny Islands, Sora and Riku's home, in which Riku sees his friends disappear without saying a word. Zexion appears and wages psychological war on Riku, telling him about how he threw away his friends and his home, opened the door to darkness, and destroyed his islands.

Following Riku's battle with a Darkside Heartless, Zexion uses his power to disguise himself as Sora and attacks him, telling him that he's become nothing more than a pawn of the darkness. He engulfs Riku in light, but a vision of Kairi (who is actually Naminé in disguise) manages to convince Riku to shed his fear of the darkness and accept both it and the light. With newfound strength, Riku follows Zexion's dark scent through the light and strikes him, but Zexion escapes. His escape is short-lived, however, as Axel brings the Riku Replica down to him and convinces the replica that he can become real by gaining power that the real Riku does not have. The replica agrees, and per Axel's suggestion, kills Zexion.

Zexion's weapon is unknown, as Nomura wants an air of mystery to surround it, to the point that the weapon panel for Zexion that would show what he wields in the World That Never Was is completely destroyed. Nomura stated in an interview he has an idea of what Zexion's weapon should be, but he will keep it to himself for now.[1]

He was originally Ansem the Wise's youngest lab assistant and test subject, under the name of Ienzo (イエンツォ, Ientso?). He was the one that convinced Ansem the Wise that they should expand the horizons of their research.

In the Chain of Memories manga, Zexion makes pickled vegetables, is described as "a surprisingly domestic type," and appears much younger than pictured here. According to the Manga, Zexion is the leader of the Underground members of Organization XIII in Castle Oblivion.