Rebirth Of A Mercenary

She was a mercenary from the modern age, who had accidentally obtained a rare treasure. However, she had been coveted by her best friend, so they joined hands to kill her.
She was the only direct daughter of the Prime Minister. Despite her superior medical skills, she was weak and incompetent. In the end, she was killed by her younger sister, who joined forces with the Crown Prince.
She had transmigrated from modern times and borrowed her body. She possessed a body immune to poisons and an excellent medical skill. She swore to make those who had harmed her pay the price!
With her intellect, the path to revenge was too simple. Destroying those people was but a gesture of a hand. However, she discovered that her best friend and boyfriend from her previous life had actually crossed over together. They were both powerful and influential in the ancient times. How could the person who betrayed her and killed her be more qualified to live than her? Since they were so concerned about power, she didn't mind playing along with the two of you …
Power, ah, isn't it power?
Later on, she helped one person obtain the entire world. Little did she know, in the end, that person had done everything in the world for her, and had suffered a crushing defeat!