MTL - General: Traveling Frog, Starting Blood and Following the Limit - Chapter 490

What happens when a scientist from a futuristic world reincarnates in a World of Magic and Knights? An awesome MC is what happens! A scientist’s goal is to explore the secrets of the universe, and this is exactly what Leylin sets out to do when he is reincarnated. Dark, cold and calculating, he makes use of all his resources as he sets off on his adventures to meet his goal. Face? Who needs that… Hmmm… that guy seems too powerful for me to take on now… I better keep a low profile for now. You want me to help you? Sure… but what benefit can I get out of it? Nothing? Bye. Hmmm… that guy looks like he might cause me problems in the future. Should I let him off for now and let him grow into someone that can threaten me….. Nahhh. *kill*-

Alternative: Leylin is transported from an advanced technological era into a medieval world— except there’s magic. Equipped with “only” his quick wits and an A.I. chip fused to his soul, he sets out to become the most powerful magus the world has ever known. In a land divided into the Light and Dark Magi, the weak can either be cattle or disposable slaves. Only the strong can determine their lives, and only they have the luxury for virtue. Yet strength is only a tool for Leylin, like any other. His goal, in the end, is his own.

The king of assassins was reborn, mastering both alchemy and poison. Sitting inside the space, there was a ghost that loved crying.

Buying a sickly boy for a hundred gold coins, becoming the master of half a country for no reason.

On their wedding night. She slightly hooked her jade finger, “Come here.”

The man tried weakly bargaining, “Can I redeem myself?”

“No!”

“Can we wait for the bridal chamber tomorrow?”

She cast a cold gaze, “Give me a reason.”

“I…..My period is here.”

Her head was covered in black lines, “Do you think you would even believe that!”

After four hours——

She weakly said, “I can’t go on anymore, wait until tomorrow.”

The man revealed an evil charming smile and turned her over before pressing down, “Want to run? Too late!”

- Description from Novelupdates

At some point in the 21st century, the Christian God stopped listening to the prayers of humanity. Monsters with colossal strength and endurance began to emerge and humanity entered its darkest period.