Jibril

is the youngest and strongest of the Flügel race. Her love towards knowledge started even before the declaration of the Ten Oaths. She opposes the book sharing law created by the Council of Eighteen Wings and left Avant Heim, her homeland, to win the National Library of Elchea from the previous king in a game. When Sora heard what happened to the library, he challenged Jibril in order to gain knowledge of the other kingdoms. When she lost the game, she became Sora and Shiro's servant since she had bet everything she owned, including herself, claiming that knowledge was worth her own life. However, she was allowed to keep the library and maintain it although she must now share it with the rest of Imanity. Thus, Jibril took the siblings as her masters and over time, she began to understand and accept Sora's belief in the potential of humanity. Unlike Steph, Jibril is happy to become the siblings' underling, and is shown to have grown feelings toward Sora.

According to Azriel, Jibril was given the gift of imperfection by Artosh and therefore named the "Exceptional unit". This gift is what Artosh believed would allow Jibril to find the answer to the Flügels' continued existence should he disappear (which was, in fact, the case).

Appearance
She has long purple-pink hair that reach down to her knees and two white wings protruding near her hips. Her pupils are purple surrounded by a gold iris but a cross shape appears in her pupils when she is focusing on a task (such as performing a spell). Her ears are wing-shaped and she also has a halo over her head. She usually has her midriff exposed and wears a long skirt. She has also a slim and well-endowed body. She has the physique of that of a 17-18 year old but in actuality is much older. After unleashing her ultimate attack, her appearance reverts to that of a young girl due to the magic recoil. Her three sizes are from above, 88, 55, 85.

Personality
She seems to be soft spoken and polite, but she can also be incredibly condescending to other races of the Exceed below her own, as shown when she indirectly insults Stephanie Dola and when she refuses to apologize to Fiel Nirvalen for wrecking havoc, also when told she had to lick Fiel's feet she refused saying she would not lick a 'mere' elf's foot. She has a great love for knowledge and gets easily excited at the prospect of gaining new knowledge, such as when she drooled over Sora's tablet after seeing the vast information it contained. Despite her initial arrogance, she has a high sense of honor while playing games, as she doesn't like cheating, or being cheated. She tends to remember the "good old days" before the oaths were established and when everything could be solved by killing, in a rather disturbing way, somewhat showing her sadistic personality.

She is also perceptive, being able uncover the weakness complex formula of Elf where none of her sister can do so, and also figure out Steph's feeling to Sora.

Unlike Steph, Jibril fully embraces her servitude to Sora and Shiro, going so far as to address them both as "Master". Throughout the anime and light novel, Jibril's feelings for Sora seem to grow, despite stating she's not supposed to have the feeling called love. Jibril first stated her feelings in Episode 10 wondering even though it's supposed to be humiliating that she licked Fi's foot, if she takes it as a order from the master she gets excited, questioning whether it could be love, before Sora interrupted her. Despite this, in Light Novel Volume 4 Jibril has expressed a willingness to merge a part of Sora's soul with her own to attempt to create a hybrid, essentially showing a willingness to bear his child. Later on, in Light Novel Volume 5, she confesses to Sora that she can finally understand love (or her perceptive of it) and has fallen in love with him.

History
Jibril is the last and most powerful Flugel created by the Old Deus Artosh and served under him until his demise. During the war of the gods she destroyed the capital of Elven Gard with a single spell known as "Heaven's Strike", which resulted in Jibril not being able to use Magic for 5 years. Afterwards Jibril stole all the books in Elven Garde despite the Elves best attempts to prevent this. Due to the loss of so many books, the Elves lost a considerable amount of magic and, as stated by Fiel, it took over 800 years to regain all the lost powers.

Sometime during the Great War, while embarking on one of her solo campaigns, she came across an Ex-Machina named Shuvi. Ex-machina heads were extremely rare prizes amongst the Flugel, because at the time there was an unspoken rule to never provoke the Ex-machina lest one seeks ruin. However, Jibril was confident she could take down Shuvi, so she had no choice but to retaliate. Despite her greatest efforts, Shuvi was ultimately defeated and killed by Jibril. However, Jibril did not escape unscathed, as she had used Heaven's Strike against Shuvi and lost all of her magic power.

After Artosh was defeated and the war concluded, Jibril lived in the Flugel city Avant Heim for some time. However with the passage of the Book-Sharing Law, she decided to leave as she did not agree with it and did not want her books passed along freely. Sometime after she challenged the Imanity King for the rights to his library, which she easily won. Jibril then stayed at her library until she was challenged by Sora and Shiro, where she lost in a game of Materialization Shiritori. In accordance with the bets for the game, she swore her very being to Sora and Shiro. Although not requested by Sora and Shiro, Jibril would go on to accept the siblings as her new masters, seemingly having replaced Artosh.

Jibril would then follow the siblings on their quest to reach Tet, the one and only God. This included helping them in their quest to acquire the Werebeast nation, Dhampir and Seiren Nation, and even a trip to her homeland, Avant Heim. Along the way, she has been documenting their actions in her own book.

Strengths
Last Unit: Artosh made Jibril in his prime during the Great War therefore, she would be the last Flugel and the strongest one at the same time. As such, she has a mass amount of strength and is able to kill races with higher rankings than herself. Even a job such as killing a Dragonia, which would take fifty Flugel she killed one herself singlehandedly, albeit, Azriel was required to constantly keep healing her.

Immortality: As a member of the Flügel race she is absolutely immortal, possessing an infinite life span: immune to all diseases, illnesses, disorders, toxins, impurities, and physical and/or mental interference; she is entirely self-sustained; will never age (always remain in her physical and mental prime) and is immune to aging abilities; she is virtually invulnerable to all harm as shown when she was shot by the elves and she only fell out of her flight course but was otherwise physically unharmed, and even if she is injured she can regenerate from any injury.

Extreme Intellect: Like the rest of her brethren, she is extremely knowledgable after valuing knowledge more than her own life after the Ten Pledges were introduced. She states that she knows more than 700 languages and is able to interpret anything.

Heaven's Strike: As a member of the Flugel race, her trump card is known as Heaven's Strike. However, it is now mostly inactive, as murder is strictly forbidden. Jibril collects the mass amount of energy into one conglomeration and aims it at something or someone. It affects a mass area and leaves a crater in place of where she casts it.

Weaknesses
Arrogance: Due to being a high-ranking race, Jibril is very dismissive of other races below her and has more confidence in her knowledge than anything else. When first meeting Shiro and Sora, she tells them that her interest in them is merely curiosity rather than respect. Her arrogance is more apparent when in their game of Materialization Shiritori, Jibril shielded Sora and Shiro against the Hydrogen Bomb, rather than being an act of kindness, she thought it'd be boring if the game ended as quickly as the first move.

Heaven's Strike: While it is her trump card, after use of it her body regresses to that of a young girl and in some cases is unable to use magic.

Quotes
"Oh yes...where are my manners, my name is Jibril. Pleased to make your acquaintance. But I'm afraid it's time for us to say goodbye."

"I apologize for calling you scrap, it was shamefully crass of me but, I have deemed your presence a threat that needs to be eliminated. You are an enemy worthy of the full extent of my power."

- Jibril about to use Heaven's Strike on Schwi

"You want my library. Does that mean you want to challenge me to a game, human?"

"Before the introduction of the ten pledges, the Flugel collected severed heads. However, now that murder is forbidden we value knowledge above anything else. It's no exaggeration to say that books containing that knowledge and the place where they are held, are as valuable as one's life. Since you're telling me to bet my life, what are you offering to bet in exchange?"

"I apologize. I hadn't considered that you Imanity would consider yourselves anything but weak."

"People from another world- no, the Imanity...they are a terrifying race."

"Oh~ I remember the Ancient War! The Dragonia, Gigant, and Old Deus storming around the battlefield. Fifty Flugel banding together and barely managing to kill a single dragon or 200 of us taking on a god and losing!~ What wonderful memories!~"

"Good evening puppy. I feel like I'm experiencing deja vu. The last time I challenged the Eastern federation and lost, were you, my opponent? Master told me to buy time, but since I'm here, let's have some fun. Throw every cheat you've got at me, and embarrass yourself to your heart's content."

Trivia

 * The author stated that Jibril is the Arabic reading of Gabriel, and that the name is not from the hentai Djibril – The Devil Angel.
 * She is the first Flugel to serve a human.