The Sickly Man I Picked Up on a Whim Is a World-Destroying Demon Lord

[Dual male leads | transmigrate and raise a child | villain who seems pure but is secretly dark, with yandere tendencies | good-for-nothing rises to power]

Mu Ci transmigrates into a cultivation novel, stuck with the classic good-for-nothing, five-spirit-root setup. He plans to wait for the System to show up and let him coast on the legendary protagonist's greatest hits.

Who could have guessed that what would fall from the sky wouldn't be a golden finger for leveling up, but a System that helps him support the villain and dish out face-slapping?

In a dilapidated servant's hut, he finds Fu Yunzheng, a young child on the verge of death, with his spiritual meridians shattered.

System prompt: Raise this future demon king, who will destroy the Three Realms, with care, and you can exchange your efforts for cultivation and techniques. If he turns evil and dies before his time, the Host's soul will be annihilated.

At first, Mu Ci only wants to coast while raising the child and earn ten thousand years' worth of cultivation. He shelters the coughing, blood-spitting child from the wind and rain, shields him from bullying within the sect, and uses a modern person's gentleness to warm the frozen demonic heart cursed by Heaven's Will.

He thinks he's merely a guardian who controls the villain's fate, unaware that the little one has already made him the only light in the world.

When Fu Yunzheng grows up, everyone fears his overwhelming demonic power and sees him as a scourge that must be eliminated.

Only this ordinary cultivator who came out of the servant's quarters dares to stand before the Demon Lord and defy Heaven's Will to protect him.

Fu Yunzheng bends down and embraces him, his eyes filled with a tenderness both obsessive and reverent:

“If the people of this world want me gone, then I'll overturn the whole world. But you, Brother, I will bow to for all eternity.”