The Extreme Alchemist of the Mighty Cauldron - Chapter 66 - : One Becomes Eight

Bai Aoxue, the best mercenary in the 21st century, is accidentally sent back to the Chengxi Dynasty in Great Continent due to an explosion in her mission, and trapped in the first daughter of Prime Minister. After her rebirth, she is set up by her father to marry the 5th prince Jun Yeyan who wears a mask all day long.
In the face of bloodthirsty enemies, discord between brothers, collusion among courtiers and invasion of enemy state, can Bai and Jun resolve the crises? What will happen to their political marriage? How will the fierce battle for the throne end?
With many twists and turns, the book brings you to experience palace revolution, love and hatred thousands of years ago.

- Description from Novelupdates

After experiencing heartbreak from being abandoned, he enlisted in the military.

And then, he became a war hero.

Earth is dying. The sun is expanding at an uncontrollable rate, but Theo Spencer is alright with this. He's led a deplorable life. When the end comes, a mysterious entity grants him the gift of reincarnation. The gift of a quiet life as an alchemist.

Theo awakens in a small town in the southern reaches of a small kingdom in a non-human body. Broken Tusk doesn't seem like much, but his legendary alchemy skills will soon turn their fortune.

Join Theo on his journey to turn the swamp-town of Broken Tusk into a prosperous trade town.