Re:Zero Kara Hajimeru Isekai Seikatsu - Arc 7 – Chapter 4, “A Brave Choice”

The protagonist of the collapse of the three former civilizations is Dr. Mei. What is the end of logic, the strongest brain, super intelligence, this is the story of the strongest scientist of Honkai with knowledge of the moon becoming the god of science!

- Description from novelbuddy

Though he received the skills necessary to teleport across worlds, the king who performed the summoning ritual attempted to trick him into wearing a slavery collar, this annoyed him so he kidnapped the princess and returned to Earth.

This thought had grown deep in William’s mind!

A cauldron, a secret forging method, and his blood created an ultimate weapon. The youngest Sword Crafting Master on Earth had been reborn from another world. With the Nine Yang Divine Furnace and a scroll of Divine Equipment, he was like a fish in water, standing at the pinnacle of the martial way. There were tens of thousands of clans, billions of cities, and countless experts. He was the master of ups and downs!