She is a half-demon human who is the leader of the K-pop group Huntrix, comprising herself, Mira, and Zoey. They assume secret identities as demon hunters to protect the human world from demons.

( Story )

Powers and Abilities

Fighting Skills:As a Demon Hunter, Rumi possesses vast experience in weapon handling and hand-to-hand combat.

Singing: As a Kpop star, Rumi is a magnificent singer, her voice is capable of attracting and inspiring hope and joy in people.

Spirit Magic: Rumi, like all hunters, can use spiritual magic; she is able to conjure weapons made of sacred energy with which she can annihilate demons.

Spirit Vision: Rumi can see spirits, demons and the spiritual energy that flows through the Honmoon, he is able to see when it changes color or fluctuates indicating that there are demons nearby.

Honmoon Creation: Rumi, together with other members of Huntrix, are capable of creating and strengthening the Honmoon using the soul energy of their fans.

Demon Magic: As a human-demon half-breed, Rumi can use demonic magic to a certain extent, but does not have full control over said powers.

Demonic Screech: When enraged, Rumi can let out a powerful scream. Due to Rumi's connection to the Honmoon, her scream affects it, sending magenta shockwaves across it.

Teleportation: Rumi, like all demons, can teleport through magenta smoke.

Demonic Patterns: Rumi possesses "patterns" on her skin, which all demons possess. It glows magenta as she loses control of her demon side, and glows a light-blue hue when she accepts her demonic side.

[Can play her as 23/24 since that is her stated age by the directors of the movie. Can also play her as 28, which is commonly accepted by fans. If you don't have a preference, canon age is default.]

from here