Ato is the third princess of the Kusharundo clan. She looks up to her brother, Kurato, and by dressing up as a boy, she could fight alongside him. After she witness Koinzell kill her brother, she couldn't accept the fact that he died and sought revenge for Kurato. She wore "The Black Dress of Vengeance" to seek revenge and tried to kill Koinzell, but eventually, she realized that Koinzell helped put Kurato out of his suffering and joined him on his quest.

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Koinzell saves Ato's life by giving her his blood, giving her some power like his.

Her arsenal of weapons include a long Dual Bladed sword and various Magical Talismans.

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Is later given a double bladed sword, crafted by Koinzell. He said her skills suited that style of weapon.