I'm not sure specifically who 'Patrick Logan' is within the context of 'Fantastic Fiction' without more information. There could be many characters or even an author named Patrick Logan in the world of Fantastic Fiction.
In the 'patrick duffy man from atlantis novel', Patrick Duffy is probably the central character. He may be a character who has a journey within the Atlantis setting. Maybe he was born there, or he somehow ended up in Atlantis. He could be on a quest to discover his own identity or to bring about some change in the world of Atlantis, facing all sorts of obstacles and making new discoveries along the way.
David Melrose is quite memorable. His actions towards Patrick as a father are so cruel and his own complex personality makes him stand out. Also, there's Nicholas Pratt. He is that kind of upper - class acquaintance who is full of snobbery and yet has his own insecurities hidden beneath the surface.
Patrick could be an ordinary boy in the bedtime story. He's the main character who experiences various adventures or has interesting encounters during his bedtime.