Gimai Seikatsu - Days With My Step Sister - Chapter 4 - 2

Only I know the end of this world.

One day our MC finds himself stuck in the world of his favorite webnovel. What does he do to survive? It is a world struck by catastrophe and danger all around.

His edge? He knows the plot of the story to end. Because he was the sole reader that stuck with it. Read his story to see how he survives!

Zhuang Feng is in his last year of high school, and he’s just moved to the city. He lives with his good-for-nothing cousin, who’s always on business trips falling for get-rich-quick scams, and his Saozi (sister-in-law), who tries to make his life miserable as much as possible. There’s one upside, though; she. is. freaking. hot. But one day, he found a piece of her underwear in the bathroom…. And unfolded a series of events that will turn his life upside down.

- Description from Novelupdates

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.

Eight hundred years ago, Xie Lian was the Crown Prince of the Xian Le kingdom. He was beloved by his citizens and was considered the darling of the world. He ascended to the Heavens at a young age; however, due to unfortunate circumstances, was quickly banished back to the mortal realm. Years later, he ascends again–only to be banished again a few minutes after his ascension.

Now, eight hundred years later, Xie Lian ascends to the Heavens for the third time as the laughing stock among all three realms. On his first task as a god thrice ascended, he meets a mysterious demon who rules the ghosts and terrifies the Heavens, yet, unbeknownst to Xie Lian, this demon king has been paying attention to him for a very, very long time.

- Description from Novelupdates