Linn Regiostar
Linn Regiostar is the father of the Church of Alexander Mark who died and became a ghost. He is apparently an RPG and dungeon crawler fanatic as he became a spirit because he died from a poison arrow trap in a dungeon he built underneath the church using all the church’s donations.
It should be noted that Viz has translated the priest’s name as “Rean Radiostar.” Before he died, he seemed particularly fond of the Ultima and Dragon Quest series, even to the point of calling himself Akiba’s “Lord British.”
At first he was spiritually bound the the dungeon, but after it was destroyed, he appears in the outside world and now moved to Nagi’s mansion, where he follows and haunts Hayate. Unfortunately for Hayate, only people who have been in the dungeon before can see him. Despite being a father he is perverted, making Hayate think things he doesn’t want to. However, he does appear in front of Hinagiku in volume 9, trying to guide her confused feelings toward Hayate, although the conclusion that she reaches is not the one that he was expecting.