MTL - Godly Alchemist - Chapter 209 Crisis resolution

In the distant future on Earth, there was a girl with God-like powers. That girl is the last survivor of the former human race that flourished in ancient times.

The Ancients.

And on that very same Earth, a new breed of humans with the ability to wield Magic emerged.

That girl began to observe the new human race silently.

Sometimes called a God, other times called Satan, that girl continued to observe the new human race.

This is the story of the happenings between the lonely girl and the hardworking new human race.

Humanity was on the brink of destruction. Muyoung, an assassin from the Forest of Death, fell to his knees. There were corpses all around him. For years, he had worked for the Forest of Death and had finally been able to eradicate them. Now, he, himself, was about to die. He closed his eyes as he felt his heart stop beating.

In the early world of immortal cultivation, there was no physical cultivation among immortal cultivators. And a top bodybuilder who came from the earth has opened up a new path here and became the ancestor of physical training.

- Description from novelbuddy

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.