Entrusted by Xemnas to look after Roxas, Axel begins to warm up to the boy, even telling him what’s on his mind during their daily break atop the clock tower in Twilight Town. However, Axel is then sent to Castle Oblivion during Kingdom Hearts: Chain of Memories, pretending to join with Larxene and Marluxia in their plan to seize control of the Organization. To gain their trust, he assassinates Vexen when ordered by Marluxia. He later derails the plans by setting Naminé free so that she can reveal to Sora the truth about how she manipulated his memory. Eventually, Axel confronts Marluxia, prepared to destroy him. Marluxia uses Naminé as a human shield to keep Axel at bay, though Axel resolves to go through her. When Sora makes a sudden appearance, Marluxia vanishes with Naminé, leaving Sora to fight Axel. Sora defeats Axel, after which he states the existence of their relation before vanishing. After Marluxia is defeated by Sora, Axel enlists the aid of the Riku Replica to get rid of Zexion in Castle Oblivion’s basement levels. When Axel returns, he and Roxas befriend Xion, the fourteenth member of the Organization who, unbeknownst to them, is in actuality an imperfect clone of Sora, Roxas’s past life, created by Xemnas. After discovering this, Roxas leaves the Organization and absorbs Xion; Axel attempts to persuade Roxas to stay with the Organization mainly out of fear of what Xemnas and the others would do to him.