Vampire: World of Blood - Chapter 3: Ichor

The world was never the same after that day.Humanity learned that they weren't alone in the universe, but that wasn't something they had the time to worry about.Their realization was accompanied by catastrophe.Creatures beyond their wildest imaginations poured down from the sky and appeared from the earth. They slaughtered humans as if it was their singular purpose, driving them to the brink of extinction.The people of the world did everything in their power, developing unique traits and technologies to create a united front their enemies couldn't penetrate.They secured victories and repopulated, feeling as if they stood a chance against the foreign invaders.They fought and they fought, doing everything they possibly could to ensure their survival.Until the Great Calamities appeared.In front of them, humanity was nothing regardless of its efforts.One by one, the worlds were turned into piles of rubble in between the cracks of their teeth. Civilization was torn apart, and the evolved humans living within could do nothing to stop its collapse.Humanity itself was left extinct, and in the end, only a single man was left alive amidst the chaos.Why?For what reason were they punished so?Nobody knew why the attacks began in the first place.He looked into the distance at the memories of the past and firmed his resolve.“It can only be me.”He knew of a miracle that could return him to the place of those memories.He knew of a way to make the wheels of time spin in reverse.And using it, he alone would save humanity from its doomed fate.That was his sacred duty as its final survivor.

More than ten years later, this sentence gradually spread in Elbaf Continent:

Never use magic to deal with tyrants, because you will find that he will return your spells to you thousands of times after being strengthened by countless magic specialties.

This is the story of a dragon-shaped self-propelled fort that keeps doing things in another world.

There is nothing that one magic can’t fix. If there is, then there are more. ——Izawa

- Description from novelbuddy

With Ye Chen, who inherited the devil, reborn the Phoenix continent, invincible, there will be any unknown secrets waiting to be solved here.
   The “City Revival Master” has been completed, and my brothers support it ~~

- Description from ~

The strongest Hero in history, Nakamoto Keisuke.

He was summoned to another world in the spring at the age of fifteen years old, and when he successfully defeated The Demon King, he was already thirty-two years old. He had finished his role in another world and returned to Japan, but the reality that had been waiting for him was, “Middle school graduate with seventeen years of blank period” label. He couldn’t find a decent job and had no choice but to spend his days working part-time.

Before such a Nakamoto, a beautiful girl who self-proclaimed had come to return the favor, appeared. “I’m the reward for Hero who had defeated Demon King”, said Angelica, a girl who came from another world that persistently tempted Nakamoto to make her his wife. Together with a high school girl who looks like Elsa, his beloved girl that he lost in another world, Nakamoto with his cheats skills got caught in a harem life.