This is a world where Witches with Magic Powers literally exist, there was the Shut-In Succubus who was specifically described as having been 'Sealed' in that book, and there was that ominous moon, I would love for his Dad to come back and just be a straight up Bloodborne Hunter who goes around hunting monsters and demons and shit. When he said he was 'An Adventurer' he was actually telling the truth. It would also be a pretty fun twist considering the one other dude who's got a bad case of Chuuni Syndrome.