MTL - The Legendary Mechanic in Marvel Universe - Chapter 50 found it

Follow Chen Ming as he accepts disciples, establishes a sect, and fights his way in a world that deems him a cannon fodder.
He goes against any common sense using his wits and novel knowhow to finish missions and arm himself against his cruel fate.

- Description from Novelupdates

Teotihuacan, a sacred place of worship. In the vast world, feel the quaint and desolate ancient city, and the eagle cries and the leopard roars are chasing away.

Go back to Central America 700 years ago, when the Aztecs were very prosperous.

The priests stood at the top of the pyramid of the sun. One hundred thousand warriors covered the entire wilderness. fluttering. The high priest held his hands high, and the obsidian dagger gleamed in the sun, drawing a cruel and gorgeous arc, bringing the cycle of life back to the earth. Tens of thousands of cheers sounded, with the reverence of the ignorant era.

This was a gift dedicated to the sun god, in return for the sacrifice of the gods in creating the world.

Solemn sacrifices from sunrise to sunset, all-night revelry ignited the whole night, and so on for a hundred years, until white-skinned terrors came from the east coast, bringing blood, thunder, monsters, and disease.

Doomsday, as legend has it, or the end of the Fifth Era?

How can a traveler, in this fierce era, inherit the legacy of two thousand years of ancient Mesoamerican civilization, resist the invasion of Western colonizers with an immortal soul, and lead the ancient Aztec civilization to a new path ~~

- Description from novelbuddy

After suffering from serious injuries, Long Chen, the son-in-law of the Li family who had been despised by everyone, suddenly underwent a shocking change. He secretly acquired extraordinary skills in both medicine and martial arts. From then on, the wheel of his fortune is about to turn...