COTE : There is Something Wrong With Hikigaya - Chapter 139: Smoke Screen

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

She is an elder miss from a modern secret society family. She is very cold and heartless, but her appearance is very enchanting. She thinks of men as playthings. She was schemed against and her body was thrown into the sea.

Six thousand years ago, Su Changsheng traveled through the fantasy world. He practiced hard and wanted to reach the peak, but he failed to even attain sainthood and was backlashed. He was disheartened, and when he wanted to die…The system was accidentally activated.‘As long as you marry a wife and have children, and develop the family, you can continue to get rewards and resources.’Su Changsheng suddenly realized the right way to advance to the peak.[You married Gu Qingge, the Empress of Destiny, and she gave birth to your first daughter. Talent: Indestructible Body, Aptitude: Peerless in the world!] [Rewards: Indestructible Body of the First Demon of All Calamities; Emperor-level Scripture!] [You vigorously developed the family and successfully promoted it to the ancient family!] [Rewards: Ancient Clan Gift Package; Luck-Golden Dragon; Imperial Weapon from Ancient Clan] [You married the Ancient Queen…] [You married Quintuplet Goddess from the Celestial Clan…]“I can have such achievements in my life, it’s all thanks to my own efforts!”Several years later, Su Changsheng, the supreme immortal master of the heavens, revered as the Great Heavenly Emperor Changsheng, humbled himself.

“Here's what happened. I was in a desperate situation when I accidentally encountered a dragon. It told me I was a martial arts prodigy and said it would teach me the Dao of Immortality…” “This excuse for skipping class and cultivating in secret… is that seriously the reason?” “I don’t care whether it’s human or not, what matters is that the dragon said: ‘If you want to become strong, kneel and call me Master.’”