I am the God of Technology - Chapter 334 Pure Heaven Sect

In the 21st century, she was the talented leader of the hidden family clan, once she crossed over, she became the number one waste?

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

Elena, who spent her entire life as a cold-blooded female knight to avenge her family, ended up dying without claiming her revenge. When she opened her eyes she found that she went back into the past. By day she was a lady in a dress, and at night she carried a sword to change history and prevent her family’s destruction.

He approached her and announced domineeringly, “Ten million, you're mine!” Little did he know that she would smash his head and flee in panic! Five years later, for the sake of her young son, she endured humiliation and became his wife, always on guard around him, “Get out, what are you doing coming in?” His handsome face darkened, “Woman, you couldn't have forgotten that we are husband and wife, could you?”