As Sora's memories are the basis of her being, Xion initially resembles Kairi, who was Sora's strongest memory at the time of her birth, though her physical appearance eventually changes depending on who is viewing her and who they have connections with. Roxas, Axel, Riku (and presumably the rest of the Organization) see her as Xion. Roxas also sees her as Sora before their battle with each other, Xigbar sees her as Ventus, Xemnas sees her as Sora, while Saïx (and also Axel, initially) sees her only as a hooded doll. As Naminé stated while talking with Riku, Xion's face was originally blank, until Sora's memories found their way into Xion and she gained an identity.
Kingdom Hearts 358/2 Days
A week after Roxas joins Organization XIII, Xemnas introduces Xion to the other members. After looking at the other members, she smiles up at Roxas, puzzling him. As Roxas departs for his first training mission, he spots Xion shyly watching him nearby, and Saïx formally introduces her to Axel and Roxas.
The day Axel is sent to Castle Oblivion, Xemnas entrusts Roxas with the task of looking after Xion, who quickly bonds with him. She reveals her ability to wield the Keyblade to him, and looks after him when he falls into a coma for several weeks in conjunction to Sora being put to sleep to regain his memories. After discovering that Sora and Riku had slain all of the Organization members (except Axel) that were in Castle Oblivion at the time, Roxas, Axel, and Xion all begin spending more time together as per Roxas's suggestion and become fast friends, such as enjoying Sea-Salt Ice Cream together. After Xion asks Axel to be her friend, and he accepts, he stops seeing her as a doll, and begins seeing her as the black-haired girl that Roxas sees.
However, a series of events begin to split the trio apart: while DiZ and Naminé oversee the restoration of the sleeping Sora's memories (moving him from Castle Oblivion to Twilight Town), Roxas begins to experience the process for himself, and begins to ponder over how he is able to wield the Keyblade and doubt the Organization's motives; Axel is reprimanded by their superiors for placing his friendship with Roxas and Xion before the Organization's goals; and Xion is thrown into disarray after a confrontation with Riku, who questions who she is and why she wields the Keyblade, causing her to become torn between staying with her friends and leaving the Organization to merge with her true self as Riku suggests.
Xion travels with Riku for several days before being captured by Axel and brought back into the Organization. However Naminé's attempts to restore Sora's memories are soon halted when Xion starts absorbing them faster, causing Roxas to weaken as she becomes stronger, as Xemnas intended. Eventually, after being tricked into fighting Roxas by Saïx, Xion decides to accept Riku's advice and leaves the Organization.
After her departure, Xion comes into contact with Naminé in Twilight Town's Old Mansion, questioning her own existence and the fate that will soon befall Roxas. She discovers that she is not a Nobody, but an imperfect Replica of Roxas. Naminé also reveals that as a memory being, once Xion returns to Sora, everyone's memories of her will inevitably be forgotten. Furthermore, Naminé's attempts to restore Sora's memories not only affect Roxas, but Xion as well, stating why they both keep having memory relapses throughout the game. Xion accepts the facts, and decides to go back to Sora. Before she does, though, DiZ barges in with the news that an Organization member has followed her, in which Xion says she will take care of it, despite Naminé's protests, and heads out of the mansion.
It is Axel who has arrived, having finally tracked Xion down. Not only is Axel curious of Xion's motives, he is also given specific orders to capture her again, which would possibly convince Roxas to return to the Organization. Xion refuses, leaving Axel no choice but to accomplish his mission with full force, leading to a heated battle. Having defeated Xion, Axel brings her back to The World That Never Was, but soon faints from fatigue. Xemnas then steps out from the shadows and carries the unconscious Xion away to reprogram her to use the devices he had planted throughout the worlds.
Soon afterward, Roxas finds Xion at the Twilight Town train station, and after she reveals her altered, Sora-like form to him, she explains that she has been compelled by Xemnas to absorb Roxas and become a "full" Sora, which would in turn prevent the real Sora from ever waking. It is explained in her Secret Reports that this is somewhat of a ruse—she knows that Roxas will disappear if she continues to exist, so she plans to force Roxas to absorb her, saving himself and thwarting Xemnas's plan. She then transforms into a monstrous version of Sora using Xemnas's devices, and attacks.
During the battle, Roxas and Xion are transported to Wonderland, Halloween Town, and Agrabah, before returning to Twilight Town. In each world, Xion absorbs power from the "devices" that were placed there, which contain memories of Sora's battles in each world. After a long and grueling battle, Roxas manages to defeat her, while she regains her original appearance in his view. When done, he doesn't seem to recall who she is, though she assures him that he'll be better off now. Cradling her in his arms, Roxas shares an emotional conversation with her, during which she explains to him that she had no regrets for meeting him or Axel, reveals the true colors of the Organization to him, and pleads with him not to let Xemnas win before dying peacefully in his arms. Saddened, Roxas suddenly remembers her name and holds Xion's hand as her body crystallizes and disintegrates into nothingness, leaving behind nothing but a single Thalassa Shell.
Though Naminé states that everyone's memories of Xion will vanish when she does, Roxas, Riku, Xemnas, and Saïx manage to retain some memories of her into the next day. By then, Roxas has returned to the World That Never Was in order to set Kingdom Hearts free, which he hopes will reunite him with Xion. However, he is being stalked by a swarm of Neoshadow Heartless, as well as a determined Riku, who has arrived to capture Roxas to finish Sora's memory restoration. Riku looks down upon the Nobody, before Roxas starts his path up the skyscraper. Through him, Xion is able to throw the Oblivion Keyblade to Riku in order to tell him to stop Roxas before he can reach Xemnas, because she believes Roxas is not strong enough to face him yet. In turn, touching the Oblivion causes Riku to recall flashbacks of the time he spent together with Xion, putting him in shock for a moment. The flashbacks then reoccur when he reaches the ground to face the Neoshadows, but this time turn blurred and grainier as they continue, until only film static remains, most likely meaning their total withdrawal from Riku's memories.
When Roxas and Riku finish eradicating the Heartless, they turn on each other for a battle. By this time, it is a struggle for Roxas to even remember Xion's name, and all he knows about her is that he wants her back. While Roxas is able to knock Riku down first, Xion then projects her words to Riku, somehow telepathically, to stop Roxas at any cost, and so he does once he removes his blindfold and transforms into Riku-Ansem. Unconscious, Roxas hears Xion talking to him through his mind, telling him not to be sad, as she has become one with him and Sora, and that soon Roxas will also join them. Despite the fact that memories of Xion have been forgotten by everyone, she tells him that she still has her own memories, so she doesn't mind that he has forgotten her, as she won't forget him or Axel. As Riku knocks him out, Roxas's last memories of Xion fade away.
Xion's Organization coat is similar to the one Roxas wears, with slightly pointed shoulders and closer-fitting sleeves. She also wears the more feminine, heeled boots that Larxene wears and the basic black gloves. Physically, Xion strongly resembles Kairi in her appearance from Kingdom Hearts, having her blue eyes and virtually the same haircut, though Xion's hair is black and her bangs part on a different side. She is slightly shorter than Roxas. As a result of her being crafted from Sora's memories, Xion's appearance is somewhat unstable, as she is known to transform into Roxas (in his Black Cloak) and both Riku and Sora in their original appearances from the first game.
Her appearance is also slightly different depending on who is looking at her. Most of the Organization, such as Saïx and, early on, Axel, view her as a hooded puppet, while to Xigbar she appears identical to Ventus. Xemnas, on the other hand, sees her true form—a perfect copy of Sora. In one of his secret reports, Axel states that Xion looks like Naminé, although it is not clear if he truly saw her as Naminé at that time, or if he simply was referring to the physical similarities that Xion and Naminé share.
PersonalityFirst arriving at Organization XIII, Xion is a shy, secluded individual. When going on a mission with Roxas, Xion begins to open up to him, and later Axel. She does seem to express emotions due to her nature of existence, and is always happy to be with her friends. However, she is somewhat emotionally fragile, becoming deeply enraged with the right provocation. After finding out the origins of her existence, she also becomes deeply confused and lost. She is observant and perceptive. She has a strong sense of justice and generosity, seen in the way she willingly gave up herself to join with Sora. She resembles Kairi and Naminé in the way that she fights to protect those she has come to care for.
Xion seems to take an interest in seashells. While Roxas was in a coma when Sora was put to sleep, Xion placed a seashell on his bedside table every day he was asleep. In her nightmare on Destiny Islands, Roxas is in the dream and picks up a shell while whispering her name. After Xion was absorbed into Roxas, all that was left of her was a single seashell. This is likely a reference to how Kairi also had a liking for seashells.
In the Jeffrey & Friends' Adventures series, since she was resurrected as a little baby (and later a little girl), Xion has developed the kind attitude of a real sweetheart. However, her old attitude still remains. She has never forgotten about her previous life as a fake Nobody and has learned to live with it, though it does bring back bad memories.
Role in the Series
Xion is diiffent to Kairi and Namine. Xion was not yet been persumed by Lord Shen. She will make a cameo in Spyro/Spongebob and Friends Get Spirited Away when illusions of her and Namine appear in Spyro's mind while he's in the World that Never Was.
Role outside the SeriesXion has a different role outside the Spongebob & Friends' Adventures series. She'll appear in the Jeffrey & Friends' Adventures series, where she is reincarnated as a baby girl. Xion will be adopted by Jeffrey. She'll later grow into a cute 6 year old little girl. After Jeffrey marries Aqua, Xion will become her adopted daughter.
Xion has also become a big sister to two sabre cubs named Tammy and Diego Jr (DJ for short), who are the daughter and son of Diego and Shira.
Xion will meet Spongebob, Patrick, Squidward, Sandy and Mr. Krabs in Jeffrey & Friends' Adventures of The Spongebob Squarepants Movie. She'll also meet The Hyenas, Spyro, Cynder, Sparx, Icky, Iago, Fidget, Po, Shifu and The Furious Five in Jeffrey, Spongebob, Spyro, Dave Felis & Friends meet Flubber. She'll see the Shell Louge Squad again in Jeffrey, Spongebob, Spyro & Friends join Underfist.