I Bound Myself to a Destructive Witch

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!"