I Have the Alchemy Emperor in My Head - Chapter 36

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates

After Xia Feng transmigrated, his heart was mysteriously removed.In its place, a defective demon heart capable of sustaining life only for eighteen years was implanted.This is a magical heart that can sync with the power level of its target.To stay alive, he bound himself to the ultimate villain of the future, a Destructive Witch who was destined to destroy the world.The stronger the Destructive Witch becomes, the stronger he becomes!Thus, Xia Feng realized, it's not my fault for stirring up trouble: “Miss Witch, I admit you're strong, but not strong enough!”

The True Spirit Continent is an era of prodigies and monstrous talents vying for supremacy. Kings roar and can make stars fall, while emperors can cover the sky with a flip of their hand. A young man named Xiao Ye, born humble, receives ancient inheritance and thus becomes the pinnacle of martial arts. He sweeps across enemies, battling through the Nine Wilds with passionate vigor, igniting the Nine Heavens with battle fervor.On the invincible battlefield, where the blood of geniuses forms a sea and monstrosities' bones pile up like mountains, Xiao Ye advances step by step, ascending to the peak, defeating all who dare proclaim supremacy in the world.As warriors, we ought to rather break than bend, decisive and resolute in slaughter, unhesitant in vendettas, and annihilate all enemies in the world!

She is the Crown Prince’s fiancee, but on the night of their wedding, an edict was made and she was given off to marry the crippled and paralyzed God of War.