Without the mysterious person, it meant that Yun Jian and Si Yi would not come to Earth, and they would not be able to bond with anyone they knew on Earth.
Killing the mysterious person before he became the mysterious person meant that they had returned to the point where nothing had started.
The mysterious person had messed up space-time, changed the course of history, and brought them together.
Then, the cloud paper would restore space-time to its original point, and everything would not happen again.
...
2004.
Walking in an era that was completely different from 2019, where there were no mobile phones and cars on the streets, the cloud paper’s mood was complicated.
She raised her hand and looked at the Fiery Red Sun hanging in the sky. It was as if she had just been reborn into Longmen City. That day, the sun was as bright and beautiful as it was today.
