The Retired Hero is an Extra - Chapter 17 - : Midnight Irregularity

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

The ordinary 18-year-old Edo, during a nighttime walk, finds himself in a fantasy world where he gains a mysterious power that could shape his destiny.

Vincent Strider was a gun for hire who made a living by killing whoever it was his clients wanted dead. But during one mission, he died in a fierce gunfight. However, death was not the end for him. Vincent found himself reincarnated in another world, facing a floating interface that flickered before his eyes.[Synchronizing Host!][Military System initializing.]Vincent found out that in this system he received, he can summon soldiers, tanks, aircrafts, and even warships! This is going to be exhilarating.

The universe gave me another chance after life screwed me over. My second life brought me to a world where people breath fire, walk on water and some people with special eyes that give them bullsh#t powers. Well, I got the gamer ability. And I’m gonna use it to stand at the peak. But it's gonna be a long journey before I reach that summit. SI - MC.