I really love the worldbuilding in this, and I love the characterisation.
if you took time to flesh out some of the MC's actions and motivations, and a more explicit reason to why he is set free I think this would easily become a story some fantasy magazines would consider
Right on. Thank you, @stuartcturnbull! I do plan to revisit this story, so I'll have a chance to see it with fresh eyes and polish it up.