Lexaeus, the Silent Hero, is number V in Organization XIII and one of its founding members. He appears in Kingdom Hearts: Chain of Memories during Riku's storyline, working with Zexion and Vexen to try and manipulate Riku into serving them. Lexaeus wields a large tomahawk in battle, using his enormous strength and the power of Earth to combat his opponents.
In Castle Oblivion
Organization XIII first appears in the series during the events of Kingdom Hearts: Chain of Memories in Sora's storyline. Much of the Organization members' activities centers around the rivalry and strife within the Organization itself. Lexaeus is heavily involved in this feud, which originates from spite between senior members of the Organization and younger members like Marluxia and Larxene.
When Larxene and Marluxia begin to show signs of dissent, Zexion and Lexaeus begin monitoring the castle and their activities. Also active in the castle are Axel and Vexen, two other members of the Organization. Axel is too unpredictable to trust, but Lexaeus and Zexion enlist Vexen's help in spying on Marluxia. After learning that Marluxia plans to make use of Sora's power by deceiving him into feeling loyalty to Naminé, they decide to make similar use of Riku.
Vexen tries to make use of Riku's power by gathering data on him and creating a replica, but his experiments are interrupted. Though he succeeds in creating the replica, he is killed by Axel on Marluxia's orders before he can achieve total control over it, and the replica becomes independent, searching for a heart.
With Vexen gone and the replica useless, Lexaeus takes matters into his own hands, and the Nobody appears to Riku shortly before Sora confronts Axel and Marluxia at the top floor of Castle Oblivion. He tries to sway the former puppet of Xehanort to give in to the darkness inside him and use his full dark powers. Riku refuses to cooperate, and Lexaeus attacks him, hoping to destroy him if he can not be manipulated. Though the battle is close, Lexaeus manages to knock Riku unconscious. However, Riku's defeat allows Ansem, Seeker of Darkness (Xehanort's Heartless) to take control and he vanquishes an unsuspecting Lexaeus. Riku is nearly overcome by Ansem, but in the end King Mickey comes to Riku's aid, and his light helps the boy regain control over his body.
Lexaeus in Battle
Lexaeus is exceptionally strong physically, and uses the element of earth to reinforce his attacks. He regularly strikes at Riku using his enormous tomahawk, and can hurl it into the air only to have it come down and flail about the combat area. Like several other Organization members, Lexaeus has the ability to levitate, which is the only magical ability he displays. He does have some other supernatural abilities, however; Lexaeus can dig out chunks of rock form the floor and heave them at Riku, and can also strike the floor with such force that it tilts.
In Kingdom Hearts II: Final Mix, Lexaeus returns as a secret boss battle along with the other slain Organization members from Kingdom Hearts: Chain of Memories. In the battle, Lexaeus and Sora each have a power meter that Lexaeus can increase. He uses a number of attacks with his tomahawk and the element of earth, which increase in damage with his power meter. Sora can use a reaction command to siphon the power away from Lexaeus onto himself.
- Lexaeus' death was altered in the new version of Kingdom Hearts: Chain of Memories. In the new version he is killed off-screen by Riku, possessed by Ansem and dies. In the original, he uses the last of his strength to attempt to swallow Riku in darkness, resulting in his own death.
- In the Japanese version, Lexaeus was voiced by popular seiyuu Fumihiko Tachiki, who was famous as the voice of Gendo Ikari of Evangelion. This marked as his first role with Square Enix.
- In the English version of the game, a Secret Ansem Report accidentally spells his original name as Eleaus.
Lexaeus in Kingdom Hearts II: Final Mix