In a semi-medieval city, an abused blind orphan boy with magical powers must stop a megalomeniac businessman before he obliterates his kingdom and his people.

Hi Benneth,
I can see that you’ve tried out a few different ways of wording this idea. I think fantasy adventures are always fun and this seems like it may be a hybrid of sorts, but it needs some clarification.
I’m not sure what a semi-medieval city is. It’s hard for me to imagine and I get hung up on trying to figure out what that is, instead of being engaged by the potential of the story.

Are we in some alternate universe where such a thing could exist? Or is there another explanation? it needs to be communicated in a succinct way within the log-line.

Also, I’m not sure how a business man exists in such a world. In a medieval setting he’d be a merchant or powerful land owner, the term businessman seems too modern for the setting your describing.

I’d centralize your hero a bit more in the logline, clarify the setting, and also add a detail about the danger: Why does your megalomanic business man want to destroy the kingdom?