Young Li Haoran tragically died after being ruthlessly betrayed by his teammates in a battle against demonic beasts. However, when he opens his eyes again, he finds himself reborn as the Blood Demon King in a tribe full of succubi. On top of that, he has acquired a special system that allows him to grow stronger simply by building a harem. This time, he will seize the opportunity, forge himself into a true demon, and lead his harem to conquer the world!