Help! Why Is My Darkened Disciple Such a Lovesick Fool?

[Two male leads + younger seme + transmigrate into a book + younger seme + both virgins + equally matched + uke as the main character] (A clingy, obedient puppy-like boy at first, later a possessive, devoted, obsessive seme, Pei Jinshen x a uke who looks cool but is always making sarcastic remarks to himself, Song You'an; one-on-one romance)

Several side couples will appear.

Song You'an transmigrates into a book and becomes a cannon-fodder character who will die alongside the future Demon God, appearing only in the final chapter.

The System forces him to redeem the gloomy, ruthless male lead, the Demon God.

Song You'an accepts his fate. He takes him in as a disciple, showers him with warmth and spiritual medicine, shields him from blades, and even takes poison for him... After a great deal of effort, he finally manages to tame the little wolf cub a bit.

But the plot is getting stranger and stranger

Is their mutual destruction a lie? Is the massacre of the Three Realms a hoax?

And is even that useless System, which keeps trying to erase him, in cahoots with his disciple?

The disciple he raised from childhood is also starting to look at him in increasingly strange ways.

Then one day, Song You'an regains all his memories and realizes that the so-called original story was an outrageous deception woven by Pei Jinshen for him alone, all to bring him back early and change the fate they were both destined to share.

He pins him against the wall, laughing in disbelief. “Explain this: the Demon God who massacres the Three Realms is actually a lovesick fool?”

Pei Jinshen pulls him tightly into his arms, his voice hoarse and obsessive. “Shizun, a world without you is utterly meaningless. This time, I want only you.”