Harry Potter: Eclipse. - Chapter 77:

Joseph Knox, one of the most prolific and well-known serial killers on the planet.A person considered so demented and manic that even trying to reason with him was believed to be a waste of time. A man so far gone that he seemingly didn't deserve any pity even on his deathbed.So why? Why would a man like him receive a second chance? And why did the world around him seem so familiar?Disclaimer: AU when it comes to some parts of Madara's plan(I'll try to make it make sense at least), and aliens don't exist in this world

I am Lin Fan and I’ve become a jack of all trades just because of a powerful Encyclopedia.
In the first ever competition organised for trolls, all the other contestants lost. The crowd exclaimed, “Brother, you’re so good at trolling.”
Lin Fan replied, “But I’ve never been trolling…”

A thousand-year dynasty would inevitably face decay, and a hundred-year noble family would eventually return to dust.What in this world could last forever?Was it an Immortal Body, tempered a thousand times, or the Martial Arts will, in Heart Unity with heaven and earth?Chen Mu came to this world, his sword in hand, and when he turned back at dusk, countless heroes and millennium-old Demons had all turned to dust, leaving only one person on the road paved with yellow sand.

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.