Kaaya is a 17-year-old oracle specializing in defensive and healing spells, first seen treating Jil's injuries after a clash with other climbers. Her support magic includes casting protective shields, boosting allies' agility and strength, mending wounds, and using insulation or freezing techniques. She activates spells through a long wand embedded with small runes and chanted incantations, though her offensive skills are restricted to a sleeping spell or barrier-breaking enchantment. Within climbing parties, she serves exclusively as a healer and defensive anchor.

As a direct descendant of Ki—the priestess who aided Gilgamesh against Druaga—Kaaya bears a striking resemblance to her ancestor. She later ascends to Uruk’s throne after the deaths of the original Gilgamesh and Neeba, fulfilling her royal lineage.

Her journey reveals profound personal growth. In the first season, she joins Jil, Ahmey, Melt, and Coopa in a climbing party, masking her true motives and identity. A pivotal collapse leads her to feign a terminal illness, concealing deeper fears about her destiny. Throughout, Ki’s spirit manifests to advise Kaaya and her allies, foretelling betrayals.

Her arc culminates across both seasons. At the end of the first season, obligation forces her to depart with Neeba, triggering a waterfall to separate Jil’s group while visibly anguished. Half a year later in season two, she confronts Jil again, expressing remorse and affirming their friendship. In this encounter, she reveals her birth name as Ishara and discloses her identity as King Gilgamesh’s great-granddaughter—Uruk’s legitimate heir—reframing her past actions as duties of lineage and throne.