The Kingdom of Flames by Audrey Everstar

In the Painted Realm, snow caresses the morning only to be devoured by the fierce blaze of summer by afternoon. Each year, the twelve banners of the realm surrender a flesh tithe to a mysterious caravan that fuels the four seasons. Their fate is unknown, save that they vanish into the clutches of the demigods in Calendar.
Yet, the seasons now wage war with growing savagery. Crops wither, food is scarce, and women are kept hidden away. The world teeters on the edge of chaos, and only the resolution of the seasons’ feud can restore harmony.
Celestine, the sole daughter of a bannerless realm, is offered as the final bride in a desperate plea to the demigods of Calendar. Her mission: to implore the seasons to restore balance and prove that the world sustaining them must be placated.
Among twelve demigods, each an embodiment of the seasons, Celestine must make her choice. They will vie for her first touch, and she will court three lords of each season. Whisked away to their immortal realms, Celestine will encounter the war, elegance, and freedom of Summer. She must choose—if she survives.

But not all demigods honor the rules. Beneath their divine allure, darker desires simmer…