One Piece: The Template System - Chapter 23: Whiskey Peak -3

After a well-lived life on Earth, Kael never expected anything more than death and the sweet embrace of sleep and darkness.But fate had other plans. He was reborn in another world similar to Earth, where he grew up until he was ten, at which point his memories from his past life were reawakened.He was an old man trapped in a boy's body, but the mixture of the child's memories with his own made him feel more middle-aged than old.A few days later, the world he was in ascended into the realm of war, the battleground of all living beings. Kael was among the few awakened who had the chance to become the ultimate god of existence, based on the orbs of different paths presented before him.Kael was faced with three choices:Orb of ChaosOrb of NothingnessOrb of Void(Choosing any will make you undergo a trial that will change your very existence. Please choose wisely.)While in shock by these options and seriously pondering which one to choose, an unexpected event occurred.(Error detected... A new option has been created)(Be the wielder of the three — Chaos, Void, and Nothingness)(Answer picked by host, transporting...)Kael was in shock as he fell into darkness, with one swirling thought in his mind:“I didn't even pick any.”

MC (female protagonist) dies in a plane crash and wakes up in the body of a beautiful but corrupt and lascivious prime minister in ancient times, Zhang Qinglian. As circumstances decree, he (she) cannot reveal that the original owner’s soul is gone else calamity might occur. So he (she) decides to walk a righteous path, determined to help the lovely but simple little emperor rule the country. Not backing down after facing torture, not losing courage, destroying rebellions and facing off with scheming princes.

- Description from Novelupdates

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.

A little ruffian who fought recklessly without any morals and bottomline accidentally time-traveled to parallel space and became a Key Case Investigation Team agent. The huge change in identity had him creating chaos in the police station. However, a strange miracle system helped him repeatedly solve mysterious cases, turning him into an impudent ruffian detective!