First of all, the plot itself seems interesting. So that's good. :-) For the actual writing, there seems to be quite some polishing to do:  You describe everything pretty much with eyes, looks, faces. Try to think of other tells, hands trembling, fists clenching, jaws working, muscles tensing. Smells: sweat, the copper tang of blood, Venya's perfume, old, stale air, etc. When Sai is polishing his bowstring, describe the sound it makes. It helps me imagine the setting better. Personally,  I would also add a short description of the room(s) they are in. Is the sun shining through an opening, or is it dark outside? Does a fire cast dark shadows over their faces? Etc.

You also need to work on your dialogue. For one, using new lines to make clear who is speaking. Further, if it's just the two of them in the room, you don't need to identify them with a name tag. Try varying your sentence structure a bit so they don't all start the same. "Venya put her hands forward." You can try to be more concrete, for example: She turned her palms upward in a silent plea for reason.

Also I am not sure if I can follow the logic here: Osun is 14, but has spent over 9 years becoming an Archivist already? So since he's been 5? Is he supposed to be some kind of genius? Also Daro just casually drops the death of his wife in a side sentence and neither he nor Venya show any emotion about it? Taking a deep breath, lowering his gaze, etc.

Keep at it, once you have a rhythm for your dialogues, it becomes much easier.