小野大輔
, is one of Nagi's former companions. He is registered as a librarian in the Mahora Library Island. Unable to leave the area for unknown reasons, he is only able to leave using replicas fueled by the world tree's magic. He admits to Eva that he spent at least ten years in rehabilitation. During the Mahorafest arc he takes the pseudonym "Ku:nel Sanders", an allusion to Colonel Sanders, stated in an omake that this is probably just because he enjoys chicken from KFC. Albireo would not respond to a person, in fact he would completely ignore them, if they did not call him "Colonel Sanders". Albireo takes delight in tormenting and playing mindgames with Eva. He's also a cunning and shrewd man, and is considered as one of the two natural enemies which Evangeline has, the other one being Nagi himself. He is voiced by Daisuke Ono.