City of Sin - Book 9, Chapter 27

Dumbledore always believed Voldemort was the greatest threat to the wizarding world until a thousand-year-old vampire showed up at Hogwarts with the deed in hand—“A thousand years have passed, and Hogwarts' lease is up!” said Dracula. “Headmaster, you wouldn't want your students to be homeless, would you?”“What do you want?” Dumbledore asked gravely.“Anything interesting.”“Well, I think the position of Defense Against the Dark Arts professor is quite interesting!”...And so, Hogwarts gained a professor who couldn’t be dismissed.McGonagall: “Albus, I don't think Professor Dracula's teaching is suitable for the poor children!”Dumbledore: “There's nothing I can do, no one can fire him.”...Draco: “My father is a governor, I'll have him get you fired!”Lucius slapped Draco on the head, “Mr. Dracula, Draco speaks without thinking. Please, don't fire the Board of Governors!”...This is the story of a vampire who lived too long and found amusement in the wizarding world out of sheer boredom.

He reincarnated into a hunter world and became an underwater hunter.There were only 20 people in the entire country in this minor profession, but it didn’t matter. He liked the sea.“Crazy! There’s a real artifact?!”“Ahahaha!! How much is all this worth!!”But then, the Great Diving Era began.“Ah, it’s so beautiful… I want to see more, more…”“W-What is that!! Save me!!!”“Aaaargh!!! My head!! It feels like my head is going to explode!!”…It would be better not to go in there.

The story starts on earth, after some unknown circumstances, the world was suddenly invaded by monsters from other worlds. Many died and even more turned into zombies, starting what many would call 'The apocalypse Era'.

Rin, a normal teenage boy who lost all of his family members was on the verge of falling into despair when a goddess appeared and sent him to another world that was very similar to a game Rin played before the apocalypse.

Her goal from this was simple, trample on all the protagonists and become the strongest creature in that world for a chance to get back what he thought he lost forever.

Accompanied by a cold beauty, both of them embark on a new journey to become stronger, get back to their world and fix everything.

Corporate slave Alexander dies with only one regret—not finishing the fantasy novel in his hands. Fate has a twisted sense of humor when he awakens as Alexander Flamingo, the perverted villain destined to be expelled and killed in that very story!Armed with complete knowledge of the original plot and a mischievous “Harem King System,” Alexander plans to rewrite his fate. No longer the one-dimensional pervert of the novel, he'll use his future knowledge to manipulate heroes, seduce heroines, and rise from disposable villain to the true mastermind of this world.The system grants him power through every relationship he builds—but can this calculating reincarnator use his second chance to avoid his predetermined death and become the ultimate Harem King? One thing's certain: this story won't follow the original script.