I think there's a very solid emotional throughline in this story, and the parallels between Iseldur and The Fox were definitely fun to pick up on and analyze, but the way it's put together lets the potential of the story down somewhat. The writing feels a bit too expository at times - in a way that comes off as somewhat dry whenever the story shifts into flashback mode, or the mythology of the world is discussed. It's well fleshed out, but there's times where it feels like the story is focusing more on giving us lore for a broader world than on telling us more about the two central characters (an example would be the comments regarding how mages typically function in the world compared to the fox spirit).
In general, it came off as somewhat odd for the fox to know so much about his own creation, the broader world, and the folklore surrounding him - it felt like it was there more for the sake of advancing the folklore theme, but I think it's a case where leaving in some ambiguity would help preserve the mystique and folkloric feel of the story, while making it a cleaner read.
Something that I'd have liked to see is more focus on the conversation between Iseldur and The Fox - I think it's a fantastic storytelling opportunity for both delivering more exposition in a natural way, and for fleshing out both characters a bit further - but as is, it felt a bit too short to be the climactic scene of the story.
Still, I think the story manages to get across some very interesting ideas in quite the short runtime - and I'm looking forward to seeing how the creator's future works!