Yu Mira is the 25th Master of the Moon Light Sword Style. She was invited to participate in the God Of High School Tournament.

Spoiler

During the World Tournament and RagnarÖk, she received Original Greed and through it Ultio R bequeath her Okhwang's physical power (which he had previously stolen). Due to that, Sang Man-Duk recognized her as the Jade Emperor's successor.

(Source: God of Highschool Fandom Wiki)