Zero no Tsukaima - Volume 12 s3Chapter 2

Alex, a special operative on Earth who died during a mission, finds himself transmigrated with the identity of an investigative journalist as an agent of a mysterious entity with a simple mission.With the promise that he would be reunited with his family once he was done, Alex accepts the offer and becomes an agent of darkness in a new world teeming with steam-powered machinery and something more... The supernatural.In this new world, he will have to navigate his way through crazy witches, bloodthirsty monsters, religious fanatics, and fallen angels while slowly making his way toward his end goal... Returning to the family he left behind.A journalist by day and a hunter by night, this is the story of the Hunter of Evernight.

Freak Xie Ao Yu originally had no way of cultivating battle qi but, by accident, he got a mysterious godly pellet and he received a supreme emperor blade. That changed his destiny and from then on, he felt the real meaning of life and he made original time and space related battle skills and decisively battled ancient, huge clans and hundreds of continental clans in the Qi Ao continent.

Clouds formed with a flip of a hand and rain formed with another flip. He left the strongest mark in tens of thousands of years of history and created glorious chapters about a tyrant’s anger, blood shed for thousands of miles, the skies hissing from mad blades, and the allegiance acknowledgement of all times.

- Description from Novelupdates

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

Despite being the ruler of a nation, nobody was willing to marry the vicious man with a bloodlust.