Ariel Anemoi Asura/Story

Volume 7 - Young Man Period - School Entry Chapter
Her first appearance was in Volume 7, as the student council president. She had given a speech during the Opening Ceremony. For most part of the volume, she usually either has Luke or Sylphiette following her around.

She was seen as a charismatic person and controlled much of the student population who saw her as an 'idol'. Rudeus had noted that her voice had a quality to it that made people feel good by listening to it.

Volume 8 - Youth Period - Special Student Chapter
She was told to have become the student council president on her first year due to her influence. Rinia Dedorudia and Pursena Adorudia who were pretty much the head before she arrived, were unhappy and led a group of students against them.

They were however, crushed by Sylphiette who was disguised as Fitts previously single-handedly.

Volume 9 - Youth Period - Sylphiette Chapter
In the chapter, it showed the beginnings the relationship between Ariel and Sylphy.

Sylphy, who fell from the sky after the Metastasis Event, saved Ariel from a Terminate Boar that was sent to assassinate her. She had wanted to thank Sylphy for saving her but Sylphy had passed out after saying her name due to the strain of using too much magic to break her fall and kill the Boar.

She wentt against her Faction who declared Sylphy dangerous or a ploy against her, saying that she refused to allow anyone to insult the person that had saved her. Due to the death of Derek in the Terminate Boar incident, the position of her Guardian Magician was open, Ariel deemed Sylphy capable and made her the next Guardian, albeit under the guise as the male "Silent Fitts".

She respects Sylphy as her savior and is shown to have a vivid imagination because she said that her 'stomach would have been torn' had she not been there.

It was revealed that she had a 'love for tormenting others', constantly playing crude pranks like asking her guards to perform their duties stark naked. It is presumed by others that she got her sadistic personality because she was constantly targetted to be killed.

She loved to target weak people like Luke while she hated to target her previous Guardian Magician Derek as she hardly got a reaction out of him. Once, she targeted Sylphy and she ended up getting attacked by her in self-defence. Sylphy had used her strongest magic against her in a half-crazed and asleep state and nearly killed her. Somehow, it awoke her masochistic side and realized she liked being tormented as much as she loved tormenting others. (this sado-masochistic trait was only slightly touched on in the Anime version, which did not include the fight between Ariel and Sylphy).

She was later forced to flee due to the growing powers of the First Prince Faction and partially because Guardian Magician Derek, who wielded quite an amount of her political power among her loyalists, had died. That had caused her to lose popularity and Philemon Notos Greyrat had pleaded for her to go to Sharia to save herself and rise up once more with connections that could rival the First Prince.

She had taken a treacherous journey towards the Ronoa Kingdom where attempts to kill her happened and at the end point, only her Guardians and two ladies, Elmore Bluewolf and Kleene Elrond remained and later became her closest attendants. The journey had made Ariel, Luke and Sylphy develop a closer bond that was even harder to break, and were comrades through and through.

When she entered the Magic Academy of Ronoa in Sharia, she was offered the title of 'Special Student' but she refused. She had wanted to start as a normal student as it would gain her more loyalty from others, seeing that she was ordinary like the rest, capable of understanding their circumstance.

She had even came up with an elaborate plan. While she was [Admiration], Luke would be her [Might]. Sylphy would be their [Mystery] as opponents would be more cautious of her as they did not know her Guardian Magician's capabilities.

It was seen that when Ariel took breaks, she would be disguised as Sylphy through the usage of a magical tool that allowed one to swap appearances. She did so to ensure that no negative influence would come upon her and the public would know next to nothing about her private life.

Throughout, she had to maintain good grades and she had the help of Luke and Sylphy for that.

She had even allowed Sylphy to reveal her identity to Rudeus, understanding how much she liked him. Her help towards Sylphy did not end there. She even schemed with Sylphy to ensure that Rudeus did know she was a female and his childhood friend, which resulted in them marrying later due to her telling Sylphy devious ways to seduce a man.

Her attitude towards Rudeus was also shown. She thought of him to be a 'powerful ally' but one that she could not control due to how strong he was. He would be a volatile ally that she could not fully trust, so she decides against having him as an ally. She felt that he would greatly boost her military power but it was not worth the risk as if he turned against her while she depended on him, it would backfire on her terribly. She is also rather well informed about his powers, knowing that he was the famed 'Quagmire'.

She is now the Queen. As the queen of Ashura, she remains a reliable ally to Rudeus, going as far as sending him her very best soldiers.

Redundancy
Rudeus says that Ariel is still unmarried because she don't want that her companion get a hold of too much power, but she have various concubine and  5 children of unknown fathers, is implied that a least one of the children is from Luke.