Seilah

"In demons' stories, the word "mercy" is nowhere to be found."

- Sayla to Elfman and Lisanna. Sayla (セイラ Seira) was a demon member 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. Around her neck is tied 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.

Despite this, Sayla has shown she enjoys being flattered by Kyouka even blushing when she praised her for supposedly destroying Fairy Tail with a lacrima bomb. She also does not like being embarrassed in front of Kyouka as shown when she is shocked that her plan did not go the way she imagined and later threatening to take her anger out on Mirajane.

History
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.

Powers and Abilities
Macro: 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.