Zense wa Kentei. Konjou Kuzu Ouji

A swordsman who lives and dies by the blade is reborn as Fay Hanse Diestburg, the third prince of Diestburg. After choosing death of his own will, he hopes to leave behind the battle-filled life he once led. Fay instead embraces a life of idleness, earning the name “Trash Prince.” But a pact with the neighboring kingdom’s Afillis royal house sends him to war as a leader of reinforcements. There, he sees a Hero with the power to overwhelm tens of thousands ravage the battlefield. Fay considers turning back, until a knight’s death stirs him to take up his sword again.