Though we aren't introduced to this character in the beginning, Unpure becomes really relevant to the story when Yuki, Sightless, & Mouthless decide to travel to a nation that idolizes humans. Unpure, a wandering spirit, joins their party for a short period of time & preaches to them about his journey to find "the truth" of his existence. Aka, Unpure is an Un that wishes to go against his name, something that Yuki has not been introduced to. Essentially, he's a homicidal, bloodthirsty, killing machine... but he wants to go down the path of happy thoughts and good wishes. In doing so, he abstains from killing and negative ideas. SAsj Just think of a priest. He's TRYING to act like a goody boy. BUT it's hilarious how he constantly fails. He's precious to me, of course, but the way he tries to keep himself "pure" is very silly & unbecoming of him. So yeah- Look forward to him.