Flash Marriage: CEO's Sweet Love - Chapter 755

Michael was suddenly reborn into a another world by a God because of an accidental death. To make up for this fact, the God gave him another life in a fantasy world of swords, magic, and monsters.Unfortunately, it turned out that the world he was reborn into was still stuck in the medieval times. It didn't have electricity, it didn't have proper plumbing, and it didn't have any technology that he was so used to back in his old world.But thanks to the God's blessing and an AI assistant called ChatJK1, he was given the power to MAKE his life comfortable. Slowly, Michael transforms this new world into a place even better than his previous one by taking ideas from the modern world and putting it in this world, with the added bonus of magic.

Seol Woon-hwi, the Blood Heaven’s Righteous Blade, rose to power, becoming second to none under the heavens, reigning just beneath the sky itself.Yet, at the height of absolute power, he finds himself returned to his past—back to his days as the scorned illegitimate child of the Everlasting Snow Palace.

Live again, earn money well, and live life slowly. General group: 841193493

- Description from novelbuddy

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates