Arua or Sola Nox is the daughter of Xe Nox, older sister of Luna Nox, and is the current ruler of Nihil's Throne. She ultimately becomes the ruler after her faction was able to defeat Luna Nox's faction when Luna disappeared with the Great Void. At some point, she is successfully able to escape from the castle to go find and save her younger sister. She ends up being able to track the remnants of Oculus's platoon to Dipluce Horizon and encounters the player SoulWorker. She ends up being captive,leaks information about Oculus's platoon and Nihil's Throne, and gives misleading information about herself. After the events of Luna Fall, she ends up staying as a captive to the Starry Forest League as she hasn't finishing tasting all of the available steak. The SoulWorker Unit and the members of the Starry Forest League are currently unaware of her true identity.
Arua was borne as Sola Nox, one of the daughters of Xe Nox. After the events of the Great Void, she becomes the ruler of Nihil's Throne as her faction was able to defeat the weakened Luna's faction due to Luna Nox's disappearance. At some point, she escapes from the castle to go search for her younger sister. She is able to locate the remnant's of Oculus's platoon to Dipluce Horizon and encounters the player SoulWorker. She fails to attack the player as she trips over a rock and the player is able to take her captive. The members of the Starry Forest League mistake her as a member of Oculus's platoon.
Arua is able to trick the group that she belongs to Luna's faction as she talked loudly regarding Luna Nox and Nihil's Throne. As part of her interrogation, she accidentally leaks information about Oculus multiple times. The members of the camp believe her to be a foolish idiot but are able to use her information to intercept Oculus's platoon. In Chii Aruel's story, she directly betrays Oculus by giving Chii information how to stop Oculus's secret ability. Throughout this time, she appears to enjoy the food that is given to her and tries to persuade the player SoulWorker into joining Nihil's Throne. Although, Shade states that this position would highly likely to be more of a slave rather than a member of the kingdom which Arua does not deny.
After the events of Dipluce Horizon, Arua is taken to Grace City as prisoner of war and secretly talks to Deltis. Deltis asks if she has sided with the humans where she affirms that she has made the correct choice. Deltis questions her on predicting Oculus movements where she states that she was able to accurately predict Oculus's movements using well-known information regarding Oculus's habits. Arua is angered that Deltis refers to her Sola, and orders Deltis to by call by Arua, the name given by her mother. Deltis does not agree since Xe Nox's order supercedes her orders and tells her to wait until her father has died. However, Deltis wonders why she didn't she play more of bigger role as she is regarded as the War Princess in Nihil's Throne but ignores it, calling it nonsense. Afterwards, the two begin to consider their next course of action since the Firestream Battalion begins to make their move towards Grace City. She tells Deltis to head back to Nihil's Throne and prepare for the war. Deltis follows up by asking if she would return to the kingdom as well. But, Arua states she plans to stay in Grace as she hasn't finished tasting human food. The conversations with Arua pleading to Deltis not to deliberately tell her father that she has rebelled against him.
