Xochitl

Xochitl (ショチトル) is a character introduced in the Toaru Majutsu no Index series. She is a member of the Aztec magic cabal known as Return of the Winged One.

Originally a girl who was not used to hurting people, her life turns around in during their cabal's attack in Liberal Arts City, where she played a supporting role but then disobeyed some commands. As punishment, she is merged with an original grimoire and is then sent out to deal with Etzali, her senior in the cabal, who has defected. The backstory of her downfall was originally referred in passing in Toaru Majutsu no Index, but is later expanded in Toaru Kagaku no Railgun SS: Liberal Arts City.

Etymology
Xochitl is a famous name in their Aztec language. It means "flower," and is ruled by the trickster god known as.

Appearance
She is a young girl from Central America. She has shoulder-length curly black hair and brown skin. In her debut she wears a red sailor uniform and had her features looked like that of an Asian. Her three sizes are B84 W58 H81.

Personality
According to Etzali, Xochitl is a girl who is not used to hurting people and hesitated in using deadly weapons. This is because of her background in dealing with the dead. Because her job was to read the residual information from the dead she knew full well the terror what weapons could do. However, that does not mean she will not do it, as shown with the mercenaries hired by BLOCK who dared cross her, dying by their own weapons through her magic. However, there is still kind side to her, as is the reason why she disobeyed commands by her superiors during their attack in Liberal Arts City, as well as help Saten Ruiko escape Kouzaku Mitori.

It is implied however that the grimoire that was merged with her influenced her will. It is unknown how much Xochitl did on her own accord.

Background
She is a member of the Return of the Winged One, and was the junior of Etzali. She had a supporting role in the organization where she was kept await from any dirty work. As the "Corpse Worker," not only does she obtain residual information from corpses and confirm whether that person’s will was accurate, she also takes of the dead by making sure everything is settled at the funeral. This job of hers would later shape her outlook regarding weapons.

After the events of October 9, two-thirds of Xochitl's has been replaced by artificial parts by the original grimoire that Etzali took possession of in order to save her.

Battle Royale Arc
With the absence of the Powered Suits due to the attack on Avignon underground organizations have begun their move against Academy City. As Aleister's loyal dogs, MEMBER also does the same. Xochitl first appears after the assassination attempt on Oyafune Monaka. She is in an open-air cafe with the Professor doing some research on a couple of papers related to the AIM diffusion fields and gives a small lecture to her about it and the possible applications that can be done with it. Baba Yoshio via his Type: Great Dane then appears before him immediately after the attempted assassination of Oyafune Monaka. He informs the Professor that SCHOOL and GROUP has made their move. The Professor asks Yoshio if they have made contact yet, to which Yoshio says that GROUP has failed at capturing them, and that it is currently unknown whether they can catch up to them. Hearing this, the Professor concludes that the other organization has made their moved as well. The Professor states that from the start organizations like them have reasons for their complex behavior, being repressed by the powers at the top and were subject to control. However, the Professor states that because of the riots that rose along with the 0930 incident, the majority of the Powered Suits were sent out to mop-up at Avignon. The Professor then says that it is a big opportunity for them as the suits cannot be used freely. Saraku then appears and asks if the opportune time will be soon, to which the Professor confirms. Xochitl then asks how the Professor could predict the other organization's movements even though the information from the higher-ups might be incorrect, to which the Professor says is because the top brass possess the technology to make that possible (most likely referring to UNDER_LINE). After the Professor sees Tsuchimikado Maika ride a cleaning robot, he becomes seriously impressed. Yoshio then says that the Professor should refrain from thinking of strange ideas.

She is absent for much of MEMBER's operations against the other organizations. She is however contacted by Baba Yoshio after the death of the Professor to come save him from the Summer Resort where he is trapped in. However, she crushes her hopes by saying that since the information he collects on the organizations is stored in different servers for each organization, she doesn't need him to pursue her enemy and she doesn't have time to clean up her mess. It is likely through this information that Xochitl was able to determine BLOCK is headed to the Reformatory, and knowing GROUP, and by proxy Etzali, will be after them there.

The mercenaries later come upon and attack her but she uses her magic to have their weapons turn against them, killing them. Not pursuing any of them, they later leave her alone as she waits for her quarry in the facility. After GROUP arrives and notices the pile of corpses at the inspection point, Xochitl calls out to Etzali who was in the guise of Unabara Mitsuki. Seeing this, Accelerator thinks she's from BLOCK, but she says that she is from MEMBER, though she just used them and had no intention of joining them. Etzali reacts to Xochitl, asking for who she is, to which Xochitl responds and says his real name. Etzali was shocked and then Xochitl finally removed her disguise. Xochitl states that she needs to thank BLOCK on account of the esper powers being halved in the Reformatory as so she doesn't need to worry with his companions getting in the way. Etzali then asks why she's there, telling her that she's not suppoed to have a spell that can do what she did (regarding the mercenaries getting killed by their own weapons). Etzali says that Xochitl was supposed to be in a position in their cabal that kept her away from any dirty work. She tells her reasons and that is to kill him as he had defected to Academy City. Hearing of this Tsuchimikado Motoharu realizes Etzali's situation. Etzali tells the rest of GROUP that he will deal with Xochitl while they go on ahead. He then tells to them her name is Xochitl, an Aztec magician who also belonged to the organization he was in before coming to Academy City. Xochitl then says that she only came for Etzali and doesn't care if they go off. However, she then says on how she wonders if "they" will let them. At that moment gunshots are heard, prompting Accelerator and Motoharu to take cover. Motoharu discovers that BLOCK's mercenaries were waiting to see what would happen between them, and asks Xochitl if they really have to deal with them but she just ignores him.

With time of the essence Accelerator tells Motoharu and Musujime Awaki to go on ahead. He tells them that he can't walk without his cane, and that he can't use his powers carelessly due to the AIM Jammer. Moreover, they can't count on Awaki's Move Point ability. He then states that it makes sense for the slowest person to stay back to hold the mercenaries off. He instructs Motoharu to provide support to Awaki as they have no idea how many people from BLOCK are inside the Reformatory, and that they need to plan on there being a large group inside they have to fight. With that their duties have been confirmed, Unabara Mitsuki (Etzali) will deal with Xochitl, Accelerator will deal with the mercenaries coming out of the building, and Motoharu and Awaki would rescue the people in the special cells.

They are later in the facility's exercise area. Here, she pulls out a feather and put it next to her ear. She then asks Etzali why he doesn't use his real face. Etzali says that he likes Unabara Mitsuki's face, and that he no longer has a right to use his face since he left the cabal. But Xochitl tells him that he doesn't even have a right to live. Feeling the deadly aura, Etzali pulled out his obsidian knife, the Spear of Tlahuizcalpantecuhtli, without thinking, though he didn't intend to use it on her right away. Then, it a shocked sounding voice, she asks Etzali what he was looking for when he came to Academy City. There, his right arm from the wrist to the elbow froze, and the obsidian knife he was holding turned towards his face against his will. Etzali immediately had his left hand seize his right wrist, and without a choice, dislocated it. In spite of the pain he was successful and he lost his grip on his knife though the feeling on his right hand disappeared. Without changing her expression Xochitl mocks Etzali and asks him to pick up his obsidian knife. Etzali believes that her spell must have been one that interfered with people's weapons and have it kill its wielder. With that disadvantage, Etzali cannot help but think that there's must be something wrong as Xochitl he knew didn't use such a spell as she was someone who was not used to hurting people. Etzali demands Xochitl on what happened to the organization to make her do this, but she did not respond. Instead, she summons her weapon, the Macuahuitl. She then says that she'll listen to whatever he'll have to say later if he's lucky enough. With that Xochitl starts towards him with the Macuahuitl, trying to cut him with the weapon without hesitation. Etzali dodges and tries to attack with his body, and is reminded of the old Xochitl who hesitated on the use of deadly weapons. As Xochitl continues to attack and mock Etzali, he tells her that the weapon she is using does not suit her. She counters his question by asking if what he is wearing suits him, the one who left the organization, hid his face, and lived in the peace of Academy City. Before he can answer, Xochitl concludes that either Etzali truly is a traitor or is only deceiving himself and have no right to say anything. With Etzali's very own eyes he sees that his junior is truly trying to kill him. She continues to attack, and says to him that it is over. She steps forward and brought the weapon at a distance from which she was sure to hit and in a timing where Etzali cannot avoid it.

Etzali however lifted his dislocated wrist above his head, and though when Xochitl saw it she believed that she had won as she put her entire weight on her weapon. The blade drew blood, tearing Etzali's jacket and the flesh of his arm. However, even though Etzali was in pain he did not die. It did not sever Etzali's arm. With that, Etzali slammed his foot into Xochitl's gut, and thus she is defeated. Here, Etzali shows the reason why he said she was not suited for her weapon as it cannot cut bone. He says that if he continued to dodge he would've eventually lost because of blood lost. With Xochitl down and weaponless, Etzali tells her that he will not kill her and says that she should just leave and go somewhere as he relocates his right wrist. Then a smile appears on her face and she collapses.

Before Etzali's very eyes, Xochitl's body begins to unravel like a bandage. Here, Xochitl says that her body has reached the limit, and says she made up for her lack of power using a grimoire. Etzali assumes that she has read one, but she says that she has done more, as their Aztec traditions hold. She has made her body into a living weapon. Etzali realizes that the true meaning of her spell is her dried flesh turned into a powder and was spread around. Still qualified as "a part of her body," it was like an extra limb through the use of magic and could control things where many of it was closely packed. Etzali knows the limits and tells her that before long her body will fail, and that no spiritual item can aid her. Xochitl says that she doesn't mind so long as she punished the one who betrayed their cabal. Etzali is enraged with his former magic cabal for their actions, and wonders what happened to them when he was gone. Xochitl can only smile as Etzali yelled while her body slowly comes apart by the power of that grimoire. Thinking of it deeper however, Etzali determines that for Xochitl to acquire something so out of the ordinary then the grimoire that merged with her must've been an original grimoire. He confirms this however after reading the words written on the inside of her skin that has come undone before them. Looking at it, Etzali screams in pain and realized that he was correct. Despite knowing of the poisonous nature of the contents of the grimoire and their indestructibility, Etzali will not allow her to die. There were many things he would like to ask of her so he will not let her die.

With that, Etzali determines that though he has no power to save her, he will have to borrow the power of the original grimoire himself to do so. Knowing the properties of original grimoires wanting to be read, Etzali will gain the ownership of the grimoire, and trick the original grimoire that it can't pass knowledge on if Xochitl dies. And from there, he can tear the original from her body. Despite that there has been a precedent for what he is about to do, Etzali does not give up just so he can save her. Etzali later successfully takes ownership of the grimoire and meets up with the rest of GROUP, all of whom were not unscathed.

Etzali later leaves Xochitl in a hospital to recuperate, with less than a third of her physical body left leaving her with nothing more than skin wrapped around a fake body. Here, Xochitl essentially becomes a hostage by the higher-ups in order to control Etzali, having two garbage men stationed to watch over her.

DRAGON Arc
Etzali visits Xochitl after 6 in the afternoon in the hospital, bringing with him traditional Aztec clothing for her to wear. Xochitl asks her if she wants him to thank him on bent knees for her gesture, to which Etzali asks what's wrong with her. Xochitl tells him however that it makes her sick that he is smiling and talking like an unrelated civilian, and asks about the grimoire if he to which Etzali confirms. She mentions that she wasn't able to control it and broke her body apart trying, though he makes it look easy. But Etzali says that he is still trying to restrain it himself using all his power. There, Etzali then asks about what happened with her and the magic cabal. Here she divulges on their cabal attacking Liberal Arts City and on how she disobeyed a few orders and as such was punished by being merged with the grimoire. Etzali asked if anyone actually tried to stop what has transpired on her and asks about Tochtli, to which Xochitl says that after merging with the grimoire she hasn't seen Tochtli. She says that Tecpatl should know where she is, but that doubts he'd let her see her. Xochitl then says on how unimaginable being merged with a grimoire, and how despite how much she has done she was still under the grimoire's will. Etzali agrees, saying that grimoires aren't meant as trump cards. He states that using them when they are not fully understood will lead to the destruction of a team, and refers to GROUP as an example which he says would kill off anyone who attempted to do something of similar nature. Hearing this, Xochitl went silent. She then asks if the comrades he was referring to was those people from before. She then blocks Etzali's mouth with her hand, telling him not to deny it. She says that no matter what his reason is, he defected to Academy City and worked willingly with the dark side of Academy City as a pawn, betraying his comrades, and defeated her, telling him that their teamwork is wonderful.

Before Etzali can reply, Xochitl averts her eyes and whispers to him, calling him Etzali onii-chan. Then, before Etzali could even react, GROUP barges into the room. Tsuchimikado Motoharu is angry at Etzali for what he has overheard. Xochitl assuming that they were from the cabal that have come to eliminate her tells Etzali to move. Before Etzali can even explain that they're on his side, Motoharu rushes up to him in irritation. He tells Etzali that even though he has someone back at his home, he dared to go to Academy City to pick up girls from Tokiwadai Middle School. Etzali tries to deny it as he shook in fright. Xochitl overhears it and asks if the reason why he betrayed the cabal was because of middle schoolers. Etzali begins to sweat and tries to avert her gaze. He then explains that his and Xochitl's relationship is like a senpai-kouhai one in the cabal, but the Siscon Sergeant, Motoharu, says that it is every man's ultimate dream. Musujime Awaki was there with them as they were trying to get Etzali for a job, but thought that it might've been better if she did it herself. Awaki says to Accelerator, that the others should consider how they feel because they are about to go into the battlefield. Accelerator murmured that he has no right to interfere with what Etzali is doing as he has some personal experience in being dragged around by brats. Awaki sighs and proclaims that she is the only one in GROUP who is not a pervert. As soon as that was said, Accelerator, Tsuchimikado Motoharu, and Etzali instantly directed their sight on her. They then claim her to be an exhibitionist shotacon, shocking Awaki and making her cough, asking them for proof that would allow them to say that she was a shotacon. They however withhold their explanations as it would be too long and just shook their heads, as if they knew all along but didn't mention it out of politeness. Meanwhile, Etzali was extremely unhappy at their surprisingly singular response, though Etzali didn't notice. She later pouts as Etzali leaves the hospital room, as he prepares to take on another job for GROUP—getting rid of terrorists who refuse to surrender.

Homecoming Arc
After the disbandment of GROUP and defeat of Tepactl, Etzali is able to save Tochtli. Apparently, Etzali has arranged for both Xochitl and Tochtli to share the same large room. Here, Etzali visits them every day without them asking, to which Xochitl finally calls him out on. Tochtli agrees, but says that if Etzali doesn't stop by one day she's sure that Xochitl would go berserk. She tells Etzali that he should keep his visits for the sake of her peaceful hospitalization. Xochitl tries to deny this, saying that she is the Corpse Worker, and as such being the hospital makes her feel left behind and making her irritated. Tochtli then says that Xochitl means that Etzali has an effect of alleviating her irritation, to which Etzali can only smile while Xochitl glares at Tochtli.

Meanwhile, Etzali cannot help but feel uneasy at the new sense of freedom he has been given, noting on how the two girls in the hospital are no longer being watched over by garbage men. He thought to himself on how the entire dark side of Academy City has been drawn back from various fields within Academy City, and all because of the change in World War III. Here, he wonders about Misaka Mikoto and the environment surrounding her that bound him more than anything else. He asks himself of he should just simply give into the peace. His thoughts however are interrupted by Xochitl, who asks him that though he understands why he took Unabara Mitsuki's face to infiltrate Academy City, what she doesn't comprehend however is on how he is still using it with his comrades. Before he can reply Tochtli cuts it, saying that he uses his face to get the information he needs from the women in the places he infiltrates as being beautiful gives one an advantage. Etzali squirms in fear at the sight of Xochitl becoming angry. He nervously tells her that Mitsuki's face is the most suitable one to approach his target with, and that he didn't choose on appearances. He adds that their disguise spell needs human skin, as such to not cause any unnecessary harm he only needs to use the face he already has. Xochitl however doesn't listen, and calls him out on his unusually polite way of speaking and states that isn't how he used to speak. Tochitl adds more coal to Xochitl's fire with a smile, saying that Etzali's job is important and that she shouldn't get mad that Etzali has become a lady-killer and she should just refer to him as "Etzal Onii-chan." Xochtil threatened him to take it off before she attempted to rip it off. Etzali can only put on a vague smile as she claws out his face.

Magic God Othinus Arc
In the final recreation of the world by Othinus created specifically to break Touma's spirit, known as the Version_Omega world in-text, where several characters from the original world have been "saved" or have not experienced great tragedy, people from the magic side like nuns are allowed to enter Academy City, and seemingly have no complex against science. Etzali, Xochitl, and Tochtli are first seen by Kamijou Touma during his "last meal" as he decides on what method he should have himself killed. Here, Xochitl asks Etzali what they should do now, but he replies that she should ask Tochtli as she was the one who heard the commotion. Tochtli then complains on how Etzali is forcing it on her as she says that Xochitl is practically his little sister. It is unknown what commotion Etzali is referring to, but is likely the festival that is happening at that time.

Toaru Kagaku no Railgun SS: Liberal Arts City
She appears in the Liberal Arts City Side Story, where there is a conflict between the Aztec Organization and the U.S. At first, Xochitl threatens to kill Saten Ruiko in order to get her to help with a small task. Later, Saten gets caught up in the conflict and the U.S. side is about to kill her, but Xochitl saves her. The objective of the organization was to destroy the Stargate Project island and the facilities on it, and Xochitl was assisting with the plan, even fighting Misaka in the process. But in the very end, she ignores the organization's orders and teams up with Misaka and the others to solve the problem.

Still loyal to the cabal, both she and Tochtli are forced to walk on a long passage to reach the place where they shall stand trial, with Tochtli nonchalant of what punishment they shall receive, concerning Xochitl. They are later displayed in a large room where many members of their magic cabal have come to judge them.

As punishment for betraying orders, over two-thirds of their body are grinded down to dust as the raw materials for an original grimoire, a derivative of the Aztec Calendar Stone, making her a living weapon. After merging with the grimoire, she was unable to see Tochtli most likely due to Tecpatl's efforts. She is then sent to kill Etzali who has defected into Academy City. Most likely because Etzali joined into GROUP, Xochitl could not find him through normal methods of intelligence gathering, she later joins MEMBER as an operative, the Academy City underworld organization directly under General Superintendent Aleister Crowley in order to use them in finding Etzali. And from there begins her search for Etzali as she wears an Asian face.

Daihasei Festival Arc
On the first day of Daihaseisai, Xochitl tries to operate the unique cellphone that is the same to the one that Shirai Kuroko uses. Confounded by the technology, Saten Ruiko overhears her and goes to her aid. However, seeing Ruiko, surprises Xochitl to the point of shouting. Ruiko seems to feel that they have met somewhere before, but because of Xochitl's disguise she couldn't tell. Xochitl then says she must be seeing things as she looks like someone she knows, confusing Ruiko. Uiharu Kazari then calls out to Ruiko that they should now leave. Before that however, Ruiko focuses her gaze on her, and tells her that she feels like that they really have met before. Xochitl insists that she is just imagining things and that she made a mistake, to which Ruiko agrees and then leaves.

The Professor then calls her and asks on what just happened, to which Xochitl says there was something she couldn't let go right away. With that done, they both get into the matter at hand, Xochitl's first job as part of MEMBER, telling her to fulfill her role and apparently knowing she is an Aztec magician. Here, he tasks her to investigate Kouzaku Mitori, the go-between they had for MEMBER and the Academy City Board of Directors. Professor suspected that Mitori may be following orders from another person and are deceiving them in order to jobs for that person.

Trying to fulfill her mission, she is with Mitori when Baba Yoshio is forced to surrender to Misaka Mikoto. She inquires Mitori on what is going on, to which she says that Yoshio is down for the count and that all her mecha pawns have been destroyed, only wanting to find somewhere safe to hide into. Mitori says that it was odd that Yoshio reports that Mikoto wasn't successfully stopped, and mentions that she will be forced to head out too. Xochitl then says that Mikoto is strong, prompting Mitori to ask if she knows her. Xochitl replies that she once saw her fight at close range. With that Mitori prepares to head out to face Mikoto, confident that she can clean up Yoshio's mess in a day.

Xochitl is in the Shinohara Liquid Metal Factory when Ruiko, investigating on behalf of Judgment 177 Branch Office decides to foolishly infiltrate the facility on her own. She gets locked inside the facility and is unable to call for help. Seeing her, Xochitl takes out her Macuahuitl, a traditional Aztec sword, and puts it up Ruiko's neck. She asks Ruiko what she was doing there, and tells her not to turn around. She instructs her to forget everything she saw and leave the place without a word. Ruiko agrees and tries to run off, but the turns around to say to Xochitl that she doesn't know how to get out on her own, angering Xochitl for not following her instructions. Suddenly, something slices up behind Ruiko, cutting her hair and bag. There Mitori's Liquid Shadow puppet appear, prompting Ruiko to flee. Mitori asks Xochitl why she let her go, to which she says that since their plan is in the final stages, Ruiko wouldn't be able to do anything at this point. However, Mitori says that that is no reason to let her leave. She tells one of the thugs there to capture the girl who ran off, worrying Xochitl. What's more, the Professor begins calling her as well.

Ruiko gets captured by the thugs. The thugs ask her what they should do with her, to which Mitori replies that after she gets to tell them what she was doing there, they can dispose of her as they see fit. Immediately after Xochitl comes to the rescue, defeating thugs easily with her Macuahuitl. Seeing this amuses Mitori, believing it to be either a betrayal by Xochitl or her caring about Ruiko. She tells Mitori that she doesn't care about that idiot behind her (Ruiko) but says the real traitor is Mitori herself. Xochitl then explains that their current mission has nothing to do with what the Academy City Board of Director wants and that Mitori is using her position as a go-between for them and the Board of Directors to coerce MEMBER to act for a client. She says that the Professor has grown suspicious and instructed her to track down her betrayal. She says that it doesn't matter where the instructions came from but she must punish a traitor.

Mitori says that if Xochitl tries to do that in the factory it would be a one-sided slaughter. Xochitl however states that Mitori may be sure that she is safe where ever she is hiding but she is not aware of all her spells. Mitori assumes that Xochitl may be bluffing but takes into account Xochitl's powers coming from outside Academy City and that she might produce some unexpected phenomenon. Not wanting to screw up, Mitori retreats. As her liquid metal puppet becomes more fluid, she gives Xochitl some advice. If Xochitl has something to return to she should leave Academy City now. Xochitl says that she has nowhere to return to, and that there is someone in Academy City that she must pursue at the risk of her own life. Mitori can only reply that Xochitl is quite a maiden. With that over, Ruiko comes toward Xochitl to thank her, now finally remembering her as the girl from yesterday, but is greeted with a bonk to her head. She tells Ruiko to not thoughtlessly approach the dark side of Acadmey City without the means to protect herself or the willingness to throw away her life. With that lecture over, Xochitl tells Ruiko to come with her as she will show her the exit.

After finding the exit, an irritated Xochitl tells Ruiko to get lost. Ruiko asks what the melty person (Mitori) was after, to which Xochitl says not to get involved. However Ruiko is persistent, forcing Xochitl to acquiesce. She then says that she doesn't know what Mitori is after as they (MEMBER) were made to act on false orders. However, it is revealed that Xochitl asked Mitori about the strange part of their "mission," and though Mitori evaded the question through how she acted, Xochitl was able to determine that she and whoever hired her wanted to use Misaka Mikoto. Their conversation is overheard by Kamijou Touma.

Abilities
She is known as "Corpse Worker" (死体職人), and her magic was originally to retrieve a dead person's will, if they have not left one prior to their death. It is said that she knows a myriad of magic to do with "death," albeit none of which can be used for attacking; she had the job of verifying if a person's will was correct after they had died.

Aztec Calendar Stone
She is merged with a derivative of the Aztec Calendar Stone, relating to the Time related to Life and Death (生と死に関する時間), replacing two-thirds of her body with the grimoire. As a living weapon, she can dry her own flesh into a powdered form and spread it around. As their Aztec magic is based around human flesh being eaten in order for it to be delivered into heaven, the dust magically still qualifies as "parts of her body". As such, as if like a limb, she can control the powder and spread it around, and it goes for the objects that the powder is concentrated on, like weapons. The force of the powder is strong enough apparently to overpower several armed men, and nearly Etzali as well.

She was in this form until Etzali took possession of the grimoire, and it granted Xochitl with artificial parts to replace the two-thirds of her body it took in order for her to live, in accordance with Etzali's ruse against it.

Others

 * Appearance Borrowing: Like Etzali, she can replace her appearance using a charm or talisman of the person she wish into using their flayed flesh, though only a small part is needed for a disguise. Xochitl disguises herself as a Asian girl. It is unknown who the girl is or if she is still alive.
 * Macuahuitl (マクアフティル): In addition to her magic, Xochitl can summon and wield a Macuahuitl out of thin air. It is a kind of weapon that Aztec warriors used as Aztec culture did not use metal for weapons. It is described as a double-edged sword made up of a wooden staff, where small stone blades made out of white chalcedony lined up on either side making it look more like a saw. Adult experts in the weapon can't cut bone with it, as such use a grazing on artery with an entire blade, and would have cut Etzali down without having to cut through his bone. As Xochitl is not used to using deadly weapons, she had no idea that she cannot cut down to the bone, as such it lead to her defeat at the hands of Etzali who led her to hit her on the bone. Etzali remarked Xochitl isn't suited for that kind of weapon.

Design evolution
Xochitl's design remains static throughout the series. According to Haimura, he didn't really give much thought to her design.

Quotes

 * (To Mitori, from Railgun Chapter 59): "It doesn't matter to me who these instructions came from, but I must punish a traitor."
 * (To Etzali, from volume 15): "I abandoned everything to come take you out because you went over to Academy City’s side, you damn traitor!"
 * (To Etzali, from volume 19): "Now over two-thirds of my body is made of artificial parts. … So how did it go? You managed to perfectly take the grimoire from me while I was unconscious. Once again you made me see your skills and magnanimity as a magician."
 * (To Etzali, ibid): "It’s nothing. When you speak of 'comrades' now, the first thing that pops up in your mind is definitely those guys that I don’t know of right?"
 * (To Etzali, ibid): "Middle-school girls? Don’t tell me you betrayed the 'organization' for a reason like that."