Hiratani Ootsutsuki

Princess Hiratani Ootsutsuki (大筒木平田に), born Hiratani Hyuuga (平田に日向), is the wife of Ashura Ootsutsuki. She lived before humanity gained natural access to chakra, however, being the daughter of Hamura Ootsutsuki, she did in fact posess chakra, and was a kunoichi.'''

Background
Hiratani was the youngest daughter of Hamura Ootsutsuki, and a princess of the Ootsutsuki empire, however could only gain sovreignty over the empire if either her five older siblings and princes Ashura and Indra all died, or if she married Indra, or if Indra died and she married Ashura. She spent quite some time trying to figure out how she was going to go about this. She was a power-hungry and feisty woman, who wanted to rule over the Ootsutsuki empire, and often participated in her uncle Hagoromo's ridiculing and abusing Indra. She spent most of her early childhood reading books about political systems and history, and scheming on how she would someday become the next Kaguya Ootsutsuki. Because of the way she behaved towards the family, her mother left Hamura. Hamura always seemed greatly hurt and worried by her behavior, however she completely disregarded any attempts at discipline.

When Hiratani was fourteen, she went to a huge party that was thrown by her great aunt, Kaguya, to welcome a group of Uzumaki royals from the neighboring kingdom. She performed a series of ninshu techniques and showed off her chakra and physical strength in every way she could in order to gain attention from the crowds. Eventually, her cousin, Ashura, told her that she needed to take a break to eat and replenish her chakra, or else she'd exhaust herself and pass out on-stage. While she was off gorging herself, she met the princess of the Uzumaki empire, Kaliel, whom she had always been jealous of for being the heir to the throne of the Uzumaki empire. She ridiculed Kaliel for not having chakra, and repeatedly claimed that the Uzumaki empire should submit to the Ootsutsuki. Kaliel slapped her and ran off. She then went back to the stage to continue demonstrating her superior knowledge of ninshu.

When Hiratani was twenty, she was married to Ashura against the latter's will; she told Ashura that if he didn't marry her, Indra would suffer for it. It was an empty threat, however Ashura, being of lower intelligence, did not realize this and complied. After the wedding, while Ashura was hopelessly drunk, she went and conversed at length with Hagoromo and said many false things about Indra, leading the Sage to become even more hateful of his elder son, and at the end of their conversation, he decided that he would leave everything to Ashura, and completely cut Indra out of his will. She later assassinated Hagoromo in his sleep, putting Ashura on the throne, and herself indirectly power. However, when war was declared against the cult of the Six Paths, and by extension, against her husband, Hiratani lost power over most of the kingdom, keeping under her power only those few thousand who followed herself and Ashura into battle. She attempted to kill Indra during the war, but was stopped by Kaliel, and the two women killed each other simultaneously.

Personality
Hiratani was extremely arrogant, attention-seeking, and power-hungry, as shown when she was willing to kill for power. She wanted to rule the world, and constantly spent time plotting how to take over her uncle's kingdom. She loved making other people feel bad about themselves, especially her cousin and brother-in-law, Indra.

Appearance
Hiratani was very tall and very thin, with long strawberry-blonde hair which she kept bound loosely and draped over her shoulder. She was usually seen wearing a long grey jumpsuit underneath a tight dark green short dress. Her eyes were Byakugan, which is to say, extremely pale lavendar.

Abilities
She was the 10th inheritor of chakra, and as such, was able to use ninshu. She specialized in taijutsu and early earth release techniques, and later developped an afinity for katon and raiton.

Kekkei Genkai
The  Byakugan (白眼; Literally meaning "White Eye", Meaning ( Viz) "All Seeing White Eye") is the  dōjutsu  kekkei genkai of the  Hyūga clan. Its power first appeared, alongside the  Rinnegan, in the oldest known ancestor of the Hyūga:  Kaguya Ōtsutsuki. [1]  It has become known as one of the Three Great Dōjutsu (三大瞳術,  San Daidōjutsu; Literally meaning "Three Great Eye Techniques"), along with the  Sharingan, and the Rinnegan. [2]

Part II
Hiratani is one off the oldest known ancestors of the Senju clan, and the wife of Ashura Ootsutsuki. Her relevance to the plot is mostly indirect.

Trivia

 * She is based on a teacher I had in grade 6. Not even kidding.
 * She is the Naruto-world insert of a character from one of my original novels, called The New Era. The character is Katanæ Ùjness.
 * Her siblings are referred to in the fanfiction she is scheduled to appear in as "1," "2," "3," "4," and "5."
 * Given that, she is the tenth naturally-born inheritor of chakra (Hagoromo, Hamura, Indra, 1, Ashura, 2, 3, 4, 5, Hiratani)
 * She wanted to kill Indra.

Reference
Well, I certainly used this guy's OC, Kaede Akarine, as a reference; Hiratani's hairstyle is based on Kaede's, as is her facial expression.