The Burning God by R F Kuang is the third and final book of her Poppy War trilogy, set in a fantasy world inspired by twentieth century China. Rin, the protagonist, has gone from poor war orphan to military leader to something far more dangerous, and the trilogy ends with a reckoning the earlier books have made inevitable.
R F Kuang has been one of the breakout fantasy writers of recent years. The trilogy is uncompromising and powerful.