Lexaeus appears in Kingdom Hearts: Chain of Memories during Riku's storyline, working with Zexion and Vexen to try and manipulate Riku into serving them. In contrast to his fighting style and physique, he is a disciplined schemer who often tries to keep people such as Vexen in line. Lexaeus appears in Kingdom Hearts 358/2 Days as a playable character in Mission Mode. Tetsuya Nomura said that Lexaeus "has slow movement, but has very high attack power".
He is No. 5 in the Organization. A born warrior, Lexaeus effortlessly brandishes a gigantic tomahawk. To counterbalance his rival Marluxia's bid for Sora's power, Lexaeus tried to conquer Riku, but was defeated by Riku's dark powers. Lexaeus first appears during Riku's storyline. He is heavily involved in the rivalry and strife within the Organization, 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 "Ansem" 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 cannot be manipulated. What happens next changes between versions.
In the original he uses the last of his strength to attempt to swallow Riku in darkness, resulting in his own death. In the updated version, though the battle is close, Lexaeus manages to knock Riku unconscious. However, Riku's defeat allows Ansem, Seeker of Darkness to take control and he vanquishes an unsuspecting Lexaeus. It is in this moment that Lexaeus realizes whom he was fighting and apologizes to Zexion, stating this was a fight he shouldn't have started.
Lexaeus is exceptionally strong physically, as shown when he is able to knock Roxas into critical health just by whacking him over the head. He uses earth to reinforce his attacks. He regularly strikes at Riku using his enormous Axe Sword, and can hurl it into the air only to have it come down and flail about the combat area. He can also throw the Axe Sword directly at the foe, which boomerangs back to him. He also has the ability to force a rock out of the ground before shattering it, leaving the pieces to fly around and damage the enemy. Like several other Organization XIII members, Lexaeus has the ability to levitate, which is one of the few magical abilities he displays.
He does have some other supernatural abilities, however; Lexaeus can strike the floor with such force that it tilts and sometimes even makes rocks fly up from the ground. Finally, he can strike the ground with such force that a damaging, unavoidable shock wave forms and spreads throughout the arena. He is incredibly tough and does not flinch from Riku's attacks after powering up, even becoming temporarily invincible if allowed to. However, he is always susceptible to special attacks, such as Riku's Dark Aura. Gaea's Gift is another one of Lexaeus's special abilities, his strength will increase 10x and he will become temporarily invincible to almost every attack Riku uses.
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. When Lexaeus increases his own meter, a large black, red, yellow, and purple aura powers up around him, protecting him from flinching, minimizing damage and pushing enemies away.
He is incredibly strong, able to throw Sora up into the air and then knock him back down, or knock Sora into a pillar and then slam him with his tomahawk. He uses a number of attacks with his tomahawk and earth, which increase in damage with his power meter. Furthermore, Lexaeus causes rocks to jut out of the ground with almost every attack, unlike the Kingdom Hearts: Chain of Memories Lexaeus, which only occasionally heaves rocks out of the ground. Sora can use the Reaction Command Mega Impact (メガインパクト) to siphon the power away from Lexaeus onto himself.
In Kingdom Hearts 358/2 Days, Lexaeus has a Limit Break called Ayers Rock. During Ayers Rock, Lexaeus can perform a charged attack. Once the Limit Break begins, Lexaeus can charge his energy, as shown by a red aura around him; he then can release the stored energy in a powerful 180-degree swing, dealing devastating damage to the target. The attack is then followed up by a shockwave. The longer the player charges before releasing this attack, the stronger the attack will be. Depending on the amount charged, this attack can even be performed twice before obtaining Final Limits.
Alternatively, the player can choose not to charge this attack at all. If so, Lexaeus will perform a less powerful swing attack with his weapon. This can be done several times during one Limit Break.
During Lexaeus's Final Limit, Lexaeus's weapon becomes engulfed in rock before releasing the charged attack, increasing the strength and range of the attack by also adding a large addition of earth to the weapon length-wise.
His Limit Break is named after the giant stone formation in Central Australia, also known as "Uluru".
WeaponLexaeus uses a massive, heavy axe sword (referred to as a tomahawk in Jiminy's Journal in Kingdom Hearts: Chain of Memories and Kingdom Hearts II), called Skysplitter, in battle. The Skysplitter is about a meter long, has a blue handle roughly as long as the blade made of black, red, and yellow metal, and appears to be laborious to use for anyone without extreme strength.
Lexaeus's attacks include mostly powerful single strikes and dives, which are often so strong that rocks are propelled out of the ground. He also has been known to throw his Axe Sword and have it boomerang back to him. Lexaeus's Axe Sword has a small Nobody symbol above the handle although it only has a single spike.
In Kingdom Hearts II Final Mix, Donald can obtain a similar weapon,
Role in the series
He has been considered to be resurrected by the Villain League. His resurrection was entrusted to Etemon for he was intended to be the perfect juggernaut one-man army to destroy the entire High Council in one fell swoop. However, Zexion secretly added his memories of the truth he learned about Xehanort's true plans, and upon Lex's resurrection, he brutally attacked Etemon and his minions, stating his honor doesn't belong to darkness anymore, and leaves. His honor sense earned him a place among Axel and the reformed nobodies. He is mostly neutral about the Lodgers whether or not they would stop Xehanort's true plans, or if they would find out at all.