Omae wo Onii-chan ni Shite Yarouka!? - Volume 3, 10th of May, Friday.

The eternal struggle between good and evil, Qin Shuang steps onto the path of cultivating, meeting various heroic individuals on her way to immortality, experiencing various events on her journey.

- Description from Novelupdates

Once upon a time, a boy was referred to as a “War Hero.”

In another world called Aletia, the boy who had saved the Lost Kingdom, conquered their neighbouring countries, and led to the rise of a grand empire decided to throw everything away, returning to the modern era at the cost of his memories.

As three years passed, the boy who was happily enjoying his daily life was once again called back to the other world.

However, what awaited him was the Aletia of 1000 years in the future.

As his past glories became a “myth,” the legend of the youth referred to as the, “Twin Black Hero King,” begins.

Su Shuilian was the first legitimate daughter of a renowned embroidery family, but she was murdered by her jealous family member. After death, Su Shuilian’s soul enters an unknown female body who lives in a dynasty she had never heard of.

While trapped in the wilderness with her wolf pup companions, Shuilian picks up an assassin who was betrayed by his organization and saves him from the brink of death.

After making it out of the dangerous forest, the two travel to a small town with few inhabitants. There, they find a location with a picturesque scenery and disguise themselves as a married couple to buy a house to settle down in.

She was a girl unfamiliar to this world, and he was an infamous assassin. Journey with them as they adapt to their new life…

- Description from Novelupdates

He was a wealthy and mysterious financial backer who had appeared before her when she needed money the most. After the courtship, she took the money and left.