Reincarnated as the Demon King's Son - Chapter 719 Incredible Power

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates

5 years after the world changed, the final boss appeared.

Once upon a time, the Devil fell in love with one of the King’s many wives. One night he went to her room disguised as her husband and made love to her. She got pregnant with his child. Knowing this The King ordered her execution believing his wife cheated on him, but then the Devil appeared to the king making him a deal. In exchange for great power for his Kingdom, the King will let his wife Sire The Devil’s Child. The King who was greedy for power agrees to the deal and his Kingdom becomes one of the most powerful Kingdoms and the Devil’s Child, the seventh Prince of the Kingdom.

“If it’s a barbarian you want, then it’s a barbarian you’ll get!”

Reclaimed by her noble family after being swapped at birth, Qin Yining is bestowed a hellish family instead. Just as she turns her situation around and gains acceptance, her country is plunged into danger instead.

Shades of gray color the world. No side is completely good, and no side is completely evil. Refusing to be a trophy won by men, Qin Yining carves her own path instead. In this absolutely riveting and spellbinding tale, what does our MC do when an entire dynasty is at stake?