War Situation. Time Travel Killer Couple

In the 26th century, the situation was turbulent and political chaos. The 17-year-old was the head of a murderous organization for money and power, and was killed by an old enemy. In the chaos of the magnetic field, she returned to an unknown dynasty that had been separated for more than 2,000 years and started anew. He lived in the troubled times when the Three Kingdoms were fighting for hegemony. He was a cold-blooded killer who killed without blinking an eye. The organization he founded made everyone in the world fear him, even the leaders of the Three Kingdoms were afraid of him. When two people meet, what happens is lingering love or tit-for-tat. The three kingdoms fight each other, and who will win in the end?