A good story, I didn't detect any major writing errors, and the idea of the story is very innovative, since the soldier boy is in Westeros, unfortunately many things are off the radar, especially how the characters are reacting to him, frankly, the what he did at the beginning of the story would already put the entire North behind his head, him also behaving kindly towards Jon or Arya seems a bit... no soldier boy, along with him being with the Starks for a long time, frankly, it's plus the soldier boy character just goes away and becomes a mercenary while completely ignoring the nobles, it's actually kind of fun watching him crush all the nobles seeking revenge for him humiliating their egos and there are also all the female characters falling in love with him because nothing, I mean... Cersei would absolutely hate him.
Other than that I really like this story, I'm looking forward to the next chapters.