Seilah

Sayla (セイラ Seira) is an Etherious of the Dark Guild Tartarus and its team: the Nine Demon Gates.

Appearance
Sayla's appearance is that of a woman, with her most noticeable feature being the two large gold-looking horns protruding from the sides of her head and pointing upwards. Upon her head is a white band which separates her hair, framing her bangs from her hair below the band. Worn upon her forehead is a small circular symbol with a small dot on the inside and surrounded by several dots around the top. Tied around her neck is a small white-colored strap.

Sayla's attire consists of a very revealing beige-colored leopard-printed kimono, bearing the decorative marks on her shoulders. The kimono is wrapped around her torso with a thick, decorative yellow ribbon that ties behind her back, and her outfit is complemented by thigh-high socks that reveal her heels and toes.

Personality
Sayla is a calm and collected person whom uses story chapter motifs in her speech. She has also displayed a cold and ruthless side to her as shown when she told Elfman that "mercy doesn't exist in the story of Demons" while forcing him to strangle Lisanna with her Curse. She is incredibly loyal, if not infatuated with Kyouka, blushing when she was praised for initially believing that she destroyed the mages of Fairy Tail. She is also ver polite, addressing her comrades with the suffix -sama. She also has a sense of pride as well as arrogance, shown when she planned to get revenge on Mirajane for ruining her reputation and shaming her in front of Kyouka.

Tartarus arc
At the behest of her Guild Master, Sayla gathers with the other members of the Nine Demon Gates at their guild headquarters. Upon the arrival of Silver and Kyouka, but noting the absence of two of their members, the group moves to show the humans the power of the underworld as brought forth by the Nine Demon Gates.

Noting their mission to assassinate the Magic Council, a member named Ezel expresses his wish for Kyouka to allow him to be the next to do so. Hearing this, Sayla tells him that there is a proper order in which things need to be done. Sayla then heads out and joins the hunting of the Magic Councilors, arriving to Yuri's home. After taking control of Yuri's body to destroy the Lacrima in Lisanna's possession, sighing, Sayla admits to herself that expecting her Curse to function particularity well was a mistake, whilst reading the book in her hands. When asked by Elfman and Lisanna to reveal her motives, Sayla simply rises to her feet and states that she merely helped Yuri reach the gates of Hell. Subsequently, she comments on how unfitting the stories humans write are for Demons, taking control of Elfman's body at the same time; forcing him to strangle Lisanna. Elfman asks her to cease her actions, with Sayla informing him that in a Demon's story, there is no such thing as mercy. As she continues to force Elfman into harming his sister, the Fairy Tail Mage tearfully begs her to stop. Hearing his request, Sayla notes that when humans ask Demons for something, it is only when they are selling their soul to them, causing her to inquire as to whether such is what Elfman is doing.

Knowing that it is, Sayla takes Lisanna from Elfman and frees him from her control. With him as her slave and Lisanna her captive, Sayla tells the Fairy Tail Mage to return to his guild with a Lacrima she provides and plant it there. Asked what it is, she reveals it to be an ultra-concentrated ether light sphere, one which is approximately 500 times as powerful as Jupiter and will destroy the guild. Shocked, Elfman claims he cannot do such a thing but Sayla replies that he can and will as her Macro is absolute.

Some time later, Sayla returns to the Tartarus headquarters, meeting with Kyouka in her chambers. Approaching the woman, who is relaxing on a sofa, Sayla inquires as to whether they have discovered the identities of those linked to Face: when Kyouka replies that thanks to Crawford Seam they have, Sayla states that they can finally stop their pointless killings. Remarking that Face is a fearsome weapon, Sayla asks if they shall locate Jellal -the final link- soon, with Kyouka believing the recently captured Erza will soon spill his location. As Kyouka comments on both the women's abilities to make people talk, she states that something needs to be done to stop Fairy Tail from intervening in their plans once more, Sayla interjecting that she has already begun to take care of that particular issue. Later, as a possessed Elfman returns to the Fairy Tail Guild, Sayla lies in bed, smiling.

Shortly after Face awaken and Tartarus' building begins to shake, Sayla heads to Kyouka and Franmalth's current location, reassuring the worried Demons that Fairy Tail will not intervene; their "story" shall soon reach its end. Standing next to Kyouka as they gaze at the Fairy Tail guild from a Lacrima-Vision, Sayla smirks as she advises the latter to pay close attention to the proceedings. Before long, the building home to the fairies bursts up into flames and Sayla tells Kyouka that it is as she has seen, earning her the woman's congratulations. However, as Kyouka begins to give them orders, Franmalth discovers many sources of Magic Power approaching Cube, prompting Sayla to display Undercube, where she notices Fairy Tail's three Exceeds approaching Cube while holding cards. Upon hearing that the cards contain all the Mages of Fairy Tail, Sayla goes wide-eyed in shock and blames herself for Tartarus' current predicament.

Soon after, Sayla happens upon the reunion of Mirajane and Lisanna, whereupon she hears Lisanna describe their ordeal. Sayla, however, corrects her assertions by stating that Elfman was not one of the Fairy Tail members they captured. Instantly recognized, Sayla reveals that Elfman was ordered to destroy the guild building, he was successful as the structure was blown up but failed due to the fact that nobody died. As a result, she was embarrassed in front of Kyouka and therefore wishes to make Mirajane pay the price. Sayla then quickly engages Mirajane in combat and overwhelms the woman with books alone, remaining relatively unharmed despite the woman using her Satan Soul; Sayla continues her assault, eventually pushing Mirajane completely onto the defensive.

Sayla eventually temporarily ceases her assault and asks Mirajane what she is, as her Macro has no effect on her; she states that with her Macro, because she can remotely resume control over something she has controlled before, she can make Elfman harm himself. However, before she can do so, a mutilated Ezel appears in the tank next to Sayla and demands that she revive him, which she refuses to do as she is in the middle of a battle. After the fact, though, Lamy explains that they're in Hell's Core and that it is Tartarus' respawn point, which prompts Sayla to chastise her. Then, when Mirajane states that her new objective is to destroy Hell's Core, Sayla wonders aloud if she can; when Mirajane does, by taking over the tentacles inside the tanks, Sayla realizes that the reason her Macro doesn't work on Mirajane is because of her Satan Soul. As neither woman can use their abilities on the other, they are forced to rely on physical combat, but before they can clash, Sayla uses her Macro on herself to release her limiter. Going forth, she strikes Mirajane faster than she can react before releasing an intense magical blast from her palm that not only obliterates what's left of Hell's Core, but greatly harms Mirajane, Lamy and Lisanna, as well as forcing the former to exit her recently-entered Sitri.

Continuing her assault on Mirajane, Sayla charges towards the Fairy Tail Mage and tackles her across the room. As Mirajane attempts to use her Take Over on the Demon once more, Sayla reminds her that it is useless, and further commands her body to tear apart the woman in front of her. After brutally slashing away at Mirajane's body, Sayla is then surprised when the Mage grabs hold of her leg, and feels herself weakening. Recognizing the danger Mirajane presents, Sayla releases her Demon Eye in a desperate attempt to erase the Mage, but before she can finish Mirajane off, Elfman appears from above and crashes into Sayla's body, instantly incapacitating her and ending the fight.

Curse and Abilities
Macro (命令, マクロ, Makuro): This Curse allows Sayla to fully control the body of her victims and manipulate them as if she was giving "orders". She has demonstrated the capacity to control both corpses and living humans, even though she stated herself that corpses subjected to her Curse do not function well. Her powers aren't solely limited to bodies, however, as Sayla has also demonstrated the ability to manipulate a multitude of books, levitating them around her person and launching them at a target with enough force to fight Mirajane's basic Satan Soul form.
 * Telekinesis: Sayla seems to possess the capability of moving objects with her hands, mainly in the forms of books. She used this as her initial offense as she threw books at Mirajane, the latter being in her Satan Soul form.
 * Limit Release: Turning her Macro ability onto herself, Sayla is able to force a transformation upon her body by commanding it to go beyond its limits. Sayla changes into a more demonic form than before, with her skin darkening and her horns growing in size. Her hair becomes much wilder, and the clothes around her torso disappears, revealing her bare chest to be covered in an intricate, symmetrical tattoo that begins at the choker around her neck, and ends at her stomach and hips. Tartarus' guild mark is printed onto her stomach, underneath a heart-shaped design in her tattoo. Her lower body significantly changes, with her legs changing into narrowed stilts that gradually widen up to her hips that now flare out into two wing-like protrusions. The transformation is ended once Sayla is knocked unconscious.
 * Energy Blast: Sayla forms two Curse mark circles around her hand, to which a third eye then grows on her open palm. From this point she is capable of generating an enormous blast of energy with enough destructive force to blow apart the majority of Hell's Core, the floor above it, and cause enough damage to Mirajane that she was forced out of her Satan Soul: Sitri form.
 * Demon Eyes: By releasing her power even further, Sayla is able to initiate a secondary transformation. By charging energy in her hands, two inscription-based wings form around her arms, and an eye appears in her palm once more. The effects of this ability remain unseen, however, as Sayla was knocked unconscious before she was able to unleash the stored energy.
 * Enhanced Speed: Sayla's speed is augmented to the point of easily surprising Mirajane, despite the Fairy Tail Mage being in her strongest Satan Soul form.
 * Flight: With the help of her ability, Sayla is shown to be able to fly at great speeds.

Quotes

 * (To herself) "The stories written by humans are boring. I shall write my own story, the story of the demons."
 * (To Elfman Strauss and Lisanna Strauss) "In a Demon's story... there's no such thing as mercy."
 * (To Fairy Tail via Elfman Strauss) "Fairies should be broken from the inside out, wouldn't you agree?"

Battles & Events

 * Elfman Strauss & Lisanna Strauss vs. Sayla