Rinne Higaki

A saint resembling a girl with long greenish, black hair who wears a long scarf-like cloth as clothing.

[Spoiler] In reality he gains the appearance and personality of those who see him and resembles those which they don't wish to remember. His appearance comes from Shichika and is a collaboration of those who he regrets losing to and his personality comes from Togame's memories. Rinne has lived for more than 300 years and was a friend of Kiki Shikizaki as he received Hakari through him. But fearing that the blade's poisonous nature he had buried it. He rather enjoys tormenting his company as they learn a little bit more about themselves through illusions until they eventually get Hakari. He wields Hakari, a sword that lacks an actual blade. [/Spoiler]

(Source: Wikipedia)