Larxene, the Savage Nymph (非情の妖姫 Hijō no Yōki , lit. Callous Vixen), is Rank XII within the original Organization XIII. Larxene is the group's only female member, and also has a very sadistic nature. She controls lightning, and uses it to thrash opponents with rapid attacks while also attacking them with her weapons: electrified throwing knives.
She is one of the members stationed at Castle Oblivion during Kingdom Hearts: Chain of Memories and is part of an internal struggle between the senior and rookie members. Larxene also appears as a playable character in the non-canonical Mission Mode of Kingdom Hearts 358/2 Days and is the first playable female character in the series.
 Between Kingdom Hearts Birth by Sleep and Kingdom Hearts 358/2 Days
On an unknown world, Larxene's original persona became a Heartless, her strong will allowing her body to continue on as her Nobody, Larxene.
Larxene was discovered by Xigbar and became the twelfth and only female member of Organization XIII. Shortly after joining, she found Axel and engaged in a conversation with him. She asked him how she looked in her new outfit, and when he did not produce a response, she took it as a sign that he found her unsatisfying to talk to. Axel explained that he was simply confused as to why she started talking to him for no reason, and that it wasn't that he found her presence unappealing, he simply found it "nothing". After a moment of silence, Larxene quietly complained that the castle was boring, and then bid goodbye to a still-confused Axel.
Some time later, she met another new member, Marluxia, with whom she is well-acquainted at this point. After asking him how he arrived at the Organization, the two neophytes agreed that the castle was boring. The discussion soon shifted to their roles in the Organization, including the importance of having hearts. In a surprisingly profound statement, Larxene said that having a heart was painful, and wondered if Nobodies like her and Marluxia were better off not regaining their hearts.
As the two walked off together, they started formulating plans to overthrow Organization XIII.
 Kingdom Hearts 358/2 Days
Larxene expressed her disgust when Roxas awoke on the seventh day and was present when Xion joined the Organization. She trained Roxas in Twilight Town before being sent away to Castle Oblivion. While tutoring Roxas, it was her responsibility to teach him how to wield magic. Larxene showed a true hatred of having to train Roxas, and seemed to loathe every moment of it. She slipped out the fact there was another Keyblade wielder besides Roxas. Upon being asked who it was, she replied, "Mind your own beeswax." Later on in the Grey Area, however, she seems to begin to acknowledge Roxas's skill, and even considers telling him about her and Marluxia's plot.
Before Axel left for Castle Oblivion, it was revealed that Saïx knew about Marluxia and Larxene's plans to overthrow Organization XIII. This is why he sent them and the other "useless" members to Castle Oblivion, along with Axel who had orders to eliminate those who planned to betray the Organization.
 Kingdom Hearts: Chain of Memories
Larxene is assigned to Castle Oblivion to help conduct experiments on memories; within this castle is Naminé, a young girl and Nobody with the ability to manipulate memories. Sora is led to Castle Oblivion by Marluxia as part of his and Larxene's plan to obtain the power of the Keyblade with which they could take over the Organization. Joining in on this plot is their fellow member Axel, one of Larxene's closer friends; however, unbeknown to her or to Marluxia, this is all a ruse on Axel's end, as he is assigned by the Organization as a double agent to gather evidence of their plan and, if their suspicions proved true, eliminate them.
As soon as Sora enters Castle Oblivion, Naminé began manipulating his memories as per Marluxia's orders; soon he begins to gain false memories of Naminé being a childhood friend until all he is unable to remember is her name. At that point, Larxene confronts Sora directly, revealing Naminé is being held hostage in the castle, and attacks him viciously, revealing a lucky charm Naminé had apparently given him years ago, motivating him into remembering her name. In reality, the charm is that of his friend Kairi, having changed shape by Naminé. Larxene fights Sora, taunting him and calling him heartless for "forgetting" about Naminé, before being defeated (something she would never admit) and escaping.
Larxene is later approached by senior member Vexen, who offers to help her, Axel and Marluxia evaluate Sora's power with a replica of Sora's best friend Riku. As per Larxene's suggestion, Vexen decides to have Naminé alter the replica's memory so that it would think it is the real Riku, much to the replica's chagrin. She even goes as far as beating up the replica to subdue it when it tries to resist. As a result, Sora clashes with the replica over protecting Naminé, thus motivating Sora into ascending further up the floors of Castle Oblivion.
Finally, Larxene and Marluxia goad Vexen into fighting Sora head on before having him killed by Axel so as to keep Vexen out of their way and to test Axel's loyalties. As soon as Axel is let in on their plot, which seems sure to come to fruition, Axel releases Naminé behind their backs, allowing her to confess to Sora. Their plot having fallen apart, Larxene reveals the nature of Naminé and the Riku Replica to Sora before attacking him in a rage. Larxene is eventually defeated in a brutal battle against Sora, this time fatally, and fades back into darkness.
The Kingdom Hearts: Chain of Memories manga depicts Larxene's death in an entirely different way. In this version, after she hits Naminé and Donald and Goofy save Sora, Donald casts a Fire spell to melt Sora's Blizzard spell while Goofy spins them around creating a sprinkler effect, getting Larxene wet. Then, when Larxene tries to use her Lightning magic, the water electrifies her instead and incinerates her.
Although Larxene is normally smiling in-game, she can be undoubtedly cold, ruthless, and uncaring, and appears to love nothing more than to bring other people down. Described the most as a domineering woman of strong personality, who does not ask, but tells, she has sharp wit and sardonic remarks ready to spite others on purpose. Her jokes tend to be more ill-humored as well, enabling anyone to successfully get irritated, and sometimes if pushed far enough, yell or charge at her in anger, a reaction which she seems to find humorous. In the Kingdom Hearts: Chain of Memories manga, Larxene was seen reading a book about the infamous French writer Marquis De Sade, the namesake of sadism, which is clearly related to her sadistic nature.
Along with the callousness, however, she oddly displays childish and playful behavior, laughing and giggling excessively. She, although recognizable with her overall behavior, also appears to have a flirtatious attitude towards Axel compared to others, with reasons for doing so not addressed. Laid back and almost passive to those she likes, or refers to as good company, Larxene expresses herself in a dramatized manner, constantly making outrageous expressions and hand movements. She taunts Vexen incessantly after he is threatened with charges of treason and incompetence from Marluxia, though that could be connected to her personal dislike of the man, and toys with Sora before fighting him the first time. In fact, she even leads Sora to believe that she is a nice person, just trying to help point him in the right direction: "The bad guys are holding her deep within the castle. And you, the hero, have to go save her." She then smiles and attacks him, sending him flying with a powerful kick and informs him that she is a "bad guy", mocking his failure to remember Naminé.
After she discovers Axel's unexpected betrayal and sees that Marluxia's and her plans have fallen apart, while affected negatively and almost seemingly disappointed when speaking of it, her friendly manner vanishes and she attacks Sora in a rage. Nevertheless, surprisingly in death, she sounds out a cry of what appears as sadness as she is fading instead of what is expected to be a usual villainous end, especially with her acts throughout the game. It showed a different side of her that had yet to be seen before that compares to Saïx's own demise. This brings to question if she truly is what she has presented herself to be the whole time, or if there is more to her.
In what may be a connection, written in one of the many Kingdom Hearts novels that correlate with the series, she meets Marluxia for the first time and has just joined the Organization as the sole female. The topic of the Organization's goal is spoken of. Being that she was the newest recruit and was asking questions, complaining that there was nothing to do around the castle, and that it was "boring" all the more, Marluxia repeated to her what Xemnas once told him; which was that they were here to regain back their hearts. She had gone silent in thought at the answer, before saying that a heart was not really necessary. She felt having one was painful, and she was fine with the way things are now, perhaps implying that she was hurt emotionally for most of her original self's life, and that lacking a heart keeps the pain at bay.
Larxene wears the normal Organization black coat and gloves, but her black boots are more feminine, with high heels. Her blonde hair is slicked back and about jaw-length, with two long strands styled into a distinctive antennae-like appearance. Larxene's eyes are a vivid green and she is very slim with an hourglass figure that sets her apart from the other members, due to her gender, though her petite appearance belies her true strength.
In her entry in Jiminy's Journal in Kingdom Hearts II, Larxene looks slightly different, as her hair is lighter, almost white, and she seems to be wearing lipstick.
Larxene is an exceptionally capable fighter; both times she talks to Sora, she is able to kick and jab him repeatedly faster than he can retaliate, and send him flying through the air with a single kick; the second time she does this, she heavily injures Sora to the point that he can barely stand. She is also strong enough to hold the Riku Replica by the head, and easily toss it across the room with one hand. Her strength is clearly known by many of the characters, such as the Riku Replica who claims to fear nothing, yet cowers at Larxene.
Larxene's physical fighting skills resemble that of a ninja. She uses her knives between her fingers to act like claws, and is able to infuse them with electricity and throw them at Sora. She is also the most agile member of the Organization, often using quick kicks and jabs to produce extra pain to the opponent. Along with her manipulative nature, this sadism earned her the title "Savage Nymph".
With magic, Larxene is able to able to call down lightning upon the battlefield, as well as to perform levitation and local teleportation. Her sleights and special abilities all involve her use of these abilities.
In Kingdom Hearts II Final Mix, she can be battled as an Absent Silhouette and as data, but this time she uses totally different tactics. She can split herself into multiple copies that attack Sora individually or in concert, and her attacks focus more on physical strikes than magic. However, she still uses some thunder magic, the strongest of which is a revolving wall of ball lightning similar to Hades's wall of fire. By using the Reaction Command "Other Break," Sora can stun her by throwing her "back into herself". This battle makes Larxene one of only five Organization XIII members shown to be able to make full-body copies of themselves, the other four being Marluxia, Vexen, Zexion, and Xemnas.
In Kingdom Hearts 358/2 Days, Larxene has a Limit Break called Voltic Rush. During Voltic Rush, Larxene rapidly slashes away at her enemies, dealing lightning damage.
During Larxene's Final Limit, Larxene darts around the field while enveloped in lightning, making her even faster. She also deals even more lightning damage to enemies.
Larxene carries a set of eight throwing Knives between her fingers in battle. Her main set of knives are collectively called Foudre, meaning "Lightning" in French. Each knife appears as one of the Organization insignia's spikes in yellow and blue. Larxene will either throw these weapons at her opponent, or speed by them, slashing them with the knives still between her fingers. The knives that she carries can also be used in close quarters combat for finishing blows. All of Larxene's knives have French names, and these names are references to natural phenomena like wind and storms. In the French version of Kingdom Hearts 358/2 Days, all of Larxene's weapons have German names.
 Notes and references