Demon Slayer Fanfic Tanjiro Kamado Fan Impromptu, Opus 3

This is an impromptu for a Demon Slayer fanfic I'm working on. This one is for Tanjiro Kamado, the main protagonist. Opus 3. The fic is still in the planning stage. It is an alternate history fic regarding the integration of the powers of Demon Slayers and Demons into a total war scenario. I'm talking WWI-style warfare but more mobile and with mass-utilized superhuman abilities. On one side, the Empire of Japan and its Demon Slayer Agency (Corps) and its allied nations like the United States. On the other, the totalitarian Eternal Horde led by Muzan Kibutsuji, with allies of its own.
Heavily inspired by Koyoharu Gotouge, Go Shiina, and Yuki Kajiura.