Maybe a Fake Gintama - Chapter 537: The Fearless Are Ignorant! The Careless Are Unconcerned!

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”!?

Every novel has a slag character, the one who decides to abandon the protagonist at his lowest, most helpless point, either because he can’t stand the poor guy’s circumstances or for other reasons. But after the protagonist wins his way in life again, they’re the ones who beg with broken sobs to be taken back.

Still, water once spilled can’t be recovered again.

Yet the unlucky Shen Jiayan has been bound to a Water Recovery* System to do just that.

*water recovery – comes from an idiom that means “spilled water can’t be recovered” (English equivalent: there’s no use crying over spilt milk).

- Description from Novelupdates

The eternal night is coming, and the killing ground descends.Gods fall, and a hundred ghosts parade at night.You can stand in the forefront and announce the arrival of the era's tide to the world, or you can hide in the darkness and coldly observe the struggle of others to survive.Liberate your thoughts, embrace your destiny, this is the absolute real game, this is, Earth's Killing Field.

Zhou Yu, a reclusive otaku, who did not like to go out of his house, was one day forced out of his house by a series of unexpected events.

- Description from Novelupdates