Aldra is the victor of the past two Queen's Blade tournaments and reigning queen. As the child of the Pope, the highest religious leader, and the granddaughter of the Devil King of the Netherworld, she is a cursed half-demon.
(From the Queen's Blade site)
The current Queen that has won the two last Queen's Blade in a row.
She's a cursed half-demon, born from the Pope, the highest-level religious leader of the earthly world, and the daughter of the devil king of the Netherworld.
Eight years ago, she summoned the demon Delmore and made a contract with it, receiving great powers beyond human knowledge, like the petrifying demon eye or the flesh-rending secret blade. It was from then on that her body stopped developing. After she became the Queen she strengthened the military control and the assassination units, and through might and power she crushed the opposition forces. Also, she sealed her left arm for fear of unleashing all her huge power.
During her childhood, while she was living a nomad life, she was separated from her newborn sister, that was everything to her. Searching for her sister, she became Queen to live a worriless life, though she found no clues about her sister in her searches. The court sorcerers predicted her sister's death, though they hid it from the Queen fearing her reaction to the news, and they stalled for time, hoping that she would be defeated in the next tournament.
Smart and with great political might, her government has a high approval rating among the population.
With her not being able to accomplish her goal, the Queen is starting to go insane for using the demonic power for so long. The high statesman noticed this and showed her a blank sheet of paper, telling her that it was a letter from her sister and that she wishes to meet with her, but she can't come to her because of several reasons.
The demon Delmore gave Aldra her power under the condition of being tied to her for the rest of her life. His worst mistake was to end up loving her, since he can't do anything in the earthly world but to heal Aldra's wounds and whisper love words in her ears. He hasn't told her, but a demon that loves a person can't go back to the Netherworld and will be destroyed when his loved one dies.