Ryou is not just an ordinary civilian, he's even weaker than one. He has the magic ring, but rarely uses it, even when given a chance.
Just become the boss and move the dam guild to wherever you want.
It doesn't work that way. Meifa won't let him have any real power. He'd just be a stud locked away and be used to provide sexual services to all the members of the dark guild, old and new. The old founder's time is long gone. Meifa wouldn't risk handing over power. She's too used to possessing it herself. If she can control Ryou, she can control all the members as well, as she would assume the duty of deciding who gets to spend time with him. With such a reward, the members would compete to pull off missions and bring money to the guild, all the time following her orders.