The Puppetmaster

A short story available free on Tor.Com.
Dark fantasy, threads of horror and sci-fi, assumed to be inspired by Japanese culture & medieval monarchies, but future set. Demons; historic weapons mixed with the futuristic (swords and axes of saltsteel, phase blasters and sun grenades); Kings & Queens; villages, monasteries; knights and servants.

All told in dual narrative - a letter and narrative of skipping timeline - some before the letter is read, the crescendo after the letter is read. Temaru, daughter of Noriko, daughter of the House of Osu Meje is the author of the letter, and it is her story.

Too short for more or there would be spoilers.
Worth your 20 minutes.

3.5 stars, rounded down