Fire in the Blood (смешанная)

For the first time in his life, Shouto Todoroki thinks he might be happy. Freed from his father's rule by the hand of his husband and now king, Shouto finds himself swept up in his lovers' embrace, the impending threat of a powerful necromancer and his undead pet with a grudge little more than a distant anxiety easily ignored for the miracle that is being loved by Katsuki and Izuku, and watching them love each other. But, as he feared, such happiness can't last.
The Todoroki kingdom has fallen, sending its monarchs retreating to the mountains for shelter and aid. With the Todorokis unseated, Katsuki finds the threat of war on his eastern border more dangerous than ever before. A mad man has taken the Todoroki kingdom and he won't rest until the whole world lies broken at his feet. Tomura Shigaraki must be stopped, but the new alliance forged between the barbarian conqueror and the disgraced flatland king is tenuous at best. As tensions mount, Shouto finds himself trapped between two levees-- on one side, his kingdom, his blood, and his legacy, on the other, his lovers, his home, and the family that made him theirs. And he has no idea where he will be standing when the floodwaters break.