Lustful Depravity: The Villain system! - Chapter 17: Oh? How interesting.

Ruins stretched across the landscape in the apocalypse after the nuclear war.

Noboru Chikara is a forsaken prince burdened by neglect and betrayal. Blamed for a devastating attack by his family to protect his siblings, he endures abuse and prejudice from his family and people of his kingdom alike as his family accuses him of being possessed by the very beast that attacked the kingdom. Driven by an unwavering spirit, Noboru sets out to reclaim his birthright and forge a new, uncorrupted kingdom. But when his father commits a heinous act, Noboru's quest takes an unexpected turn, propelling him into a realm beyond imagination. Follow Noboru's journey as he transcends dimensions and becomes the one who bring peace to all dimensions higher or lower and become The God Of Fiction.

After an accidental death, in order to continue to live, Gu Bai had to choose to go through various wonderful books to complete tasks.

Every time he became a variety of small cannon fodder inside the story, Gu Bai’s code of conduct when completing task is – by all means, don’t be inferior, don’t be shameless, don’t be upright… hold on to a golden thigh.

… N times after transmigrating

Cannon fodder: (angry contempt) … You’re already so powerful, why are you still shamelessly holding on to a golden thigh to deal with us!?

Gu Bai: (deadpan) That… holding and holding… got used to it…

- Description from Novelupdates

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?