Xu Qianqiu transmigrates to a world where humans and demons coexist. He starts as the crown prince of a kingdom, but this kingdom is facing a demon invasion, with over forty cities already lost. The king orders him to lead the army against the demons. Luckily, the strongest killing system activates, allowing him to fuse the power of the Overlord. From then on, this world has a new, insane killing god! He gains rewards such as the Eighteen Riders of Yan Yun, the Tiger Roar Dragon's Cry Iron Cloth Shirt, and even a character card of Li Cunxiao for each demon he slays. Xu Qianqiu leads his army to victory, reclaiming lost territories. But just as he's about to reach the demons' lair, the court signs a peace treaty with the demons and orders him to retreat. Xu Qianqiu's gaze...