Rin appears as a young girl with long blonde hair, usually tied in a large ponytail, despite being over 800 years old. She stands between 5.0 and 5.3 feet tall. As the last living original Idaten and sole survivor of the battle against the demon tribe eight centuries ago, she is now the strongest Idaten alive, guarding the seal that imprisons the demon tribe.

Her primary focus is training new generations of Idaten, like Hayato and Prontea whom she summoned. This training is brutally extreme, involving beating trainees nearly to death to prepare them for combat, overcome physiological limits, desensitize them to pain and organ damage, and enhance their effectiveness. Rin typically stays near the demon seal but travels worldwide rapidly to find new summoning locations.

She possesses unmatched physical power, capable of destroying entire nations and reshaping landscapes. Her extraordinary speed allows her to circle the globe in minutes and venture into space and back within seconds. Rin can manifest weapons from her body, primarily a devastating sword that can split regions. Additional powers include manipulating her weight from zero to infinite, limitless growth potential through training, invulnerability to conventional fatal injuries, and rapid regeneration—regrowing dismembered limbs in seconds. She operates without needing nutrients, oxygen, or rest due to inexhaustible stamina.

Considered exceptionally violent even among Idaten who show little regard for humans, Rin once suggested annihilating the Zoble Empire and its 70 million inhabitants to eliminate 300 demons, alarming other Idaten. Despite this brutality and her singular focus on eradicating demons, she cares deeply for fellow Idaten, viewing them as siblings requiring her protection and guidance.