Isekai de Kojiin wo Hiraitakedo, Nazeka Darehitori Sudatou to Shinai Ken (WN) - Chapter 55: Strategy meeting!

Zong Shou woke up from a dream and realised that he had time traveled back ten thousand years, to an era before the God Emperor was had appeared in the world.

“Marry me under the conditions that we will divorce in 5 years.”

She, a 21st century mercenary queen, had crossed over into a tragically betrayed body of a waste. Waste? She will show them what it means to be a waste! Betrayed? With the Ancient Manual in her hands, she will astonish all the despicable men and cheap women!

Wait! Didn’t everyone say that she was an evil woman which everyone feared? Why is his Third Highness, full of mystery and charisma, so interested in her?

- Description from Novelupdates

Roy died during a war against the Evil God Cult, but somehow, he returned back in time to 30 years in the past where he was just a boy who awaken his summoning magic.