This is shown to be nothing but a ruse, in connection to her thoughts by her Secret Reports. She (Xion) is aware that they cannot coexist, that Roxas was in danger if so, and decided to willingly disappear, and not let Xemnas succeed: a fact that she states when she later dies.
Knowing that Roxas would not be able to kill her, and Axel had admitted that he could not either in his own Secret Report, she forces Roxas to fight her instead. Xion then transforms into a giant armored monster at the ready. After a long and grueling battle, Roxas defeats Xion, who regains her original appearance. Roxas, however, loses all of his memories of Xion after the battle. In her final moments, she informs Roxas of the true colors of the Organization, tells him that she is glad they were friends and pleads with him not to let Xemnas accomplish Kingdom Hearts before dying peacefully in his arms. At this moment, Roxas remembers Xion, but he is too late. Saddened, Roxas holds Xion's essence and degenerating crystallized body until she is completely gone, leaving behind a seashell on the ground, as he spills tears.
This marks the start of where he gains his signature ability to dual-wield, as he awakens Ventus's Keyblade after Xion's demise. The first time he uses them, they appear as two Kingdom Keys, his and Ventus's, which quickly transform into the Oathkeeper & Oblivion.
Knowing that Roxas would not be able to kill her, and Axel had admitted that he could not either in his own Secret Report, she forces Roxas to fight her instead. Xion then transforms into a giant armored monster at the ready. After a long and grueling battle, Roxas defeats Xion, who regains her original appearance. Roxas, however, loses all of his memories of Xion after the battle. In her final moments, she informs Roxas of the true colors of the Organization, tells him that she is glad they were friends and pleads with him not to let Xemnas accomplish Kingdom Hearts before dying peacefully in his arms. At this moment, Roxas remembers Xion, but he is too late. Saddened, Roxas holds Xion's essence and degenerating crystallized body until she is completely gone, leaving behind a seashell on the ground, as he spills tears.
This marks the start of where he gains his signature ability to dual-wield, as he awakens Ventus's Keyblade after Xion's demise. The first time he uses them, they appear as two Kingdom Keys, his and Ventus's, which quickly transform into the Oathkeeper & Oblivion.
![](http://fc00.deviantart.net/fs70/f/2013/058/e/7/sora_vs_roxas_by_sonny92kh-d5wf4du.gif)