Book Arkady Saulski. Red Lotus

People tell tales of how the elder Spirits abduct children to alter their minds and turn them into ruthless warriors. They say their souls are replaced by demons, and spells are cast upon their bodies to numb them to pain. Some even claim that the Spirits themselves become entwined with the bodies of these children, subjecting them to irreversible changes—making their abilities far beyond those of ordinary mortals. In every folktale, legend, or fable, there lies a grain of truth." "Kentaro had one purpose in life: to protect his mistress. But he had failed. Given a second chance, he had to make the most of it. Defend his new family and stand against the savage invaders ravaging the land. For one Spirit was worth more than a hundred samurai. He had to seek vengeance against the only person capable of saving Nippon from barbaric oppression." "Kentaro had to do just that. However, the legends fail to mention that Spirits remain human, capable of love and hatred. Just like everyone else, only much stronger."