Ato is the third princess of the Kusharundo clan. Admiring her brother Kurato, she disguised herself as a boy to fight by his side. After witnessing Koinzell end her brother's life, she refused to accept his death and embarked on a quest for vengeance. Donning "The Black Dress of Vengeance," she attempted to kill Koinzell but eventually understood that Koinzell had freed Kurato from his suffering and joined him on his journey.
Koinzell saved Ato's life by giving her his blood, granting her powers similar to his own. Her arsenal includes a long dual-bladed sword and various magical talismans. Later, Koinzell crafted a double-bladed sword for her, noting that her skills were well-suited to this weapon style.
