Picked up the Last Dragon

Xian Yu traveled through time and became a small lord of a territory. After learning that the industrial development of this world was backward and there were no so-called fantasy elements, he laughed. In this world where the steam engine has not yet appeared, he will set off an industrial craze. He will be remembered and praised by the world. He will become a pioneer in the world... Hey, wait, how did the steam engine be built? What is the best recipe for gunpowder? How is cement made? "If I had known I could time travel, I would have mastered the knowledge related to physics and chemistry and mechanical structures when I was in school!" Wait a minute! Why is there a dragon here? Where did this elf come from? And what is that thing flying in the sky with a pair of wings? It was said to be just an ordinary feudal society with backward industry. Why did my spiritual energy start to recover as soon as I arrived? !