ATG: My genius is almost frightening! - Chapter 3: Domain expansion.

A teenager named Evan Mason was reincarnated into the magical world of Harry Potter and goes to school at Hogwarts!
With only his knowledge of the future and great talent for magic, he takes the path towards the top of the magic world, only to realize that ever step he took, changed everything!

- Description from Novelupdates

For his sake, she was willing to abandon her career as the best actress and be his wife. With her own network, money and unscrupulous methods, she helped him rise to the top of the world. He, on the other hand, held another woman in his embrace and kicked her away with no mercy. It turned out that all he ever wanted was her rare blood type, her six-month-old child’s cord blood. It was her life… When she opened her eyes again, she returned to her 20-year-old self. Time repeated and her life rewound. In this life, she would live well.

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?

Zhong Yuhuan had transmigrated into a book and became the female supporting character who was destined to die an untimely and tragic death. Coincidentally, her family adopted two boys — the male lead and the villain of the book!

The male lead of the book would become a superstar in the show business and the villain a super successful and powerful businessman.

Zhong Yuhuan thus began her life of raising the male lead and the villain while faceslapping other scums. She would grow up quickly and live the life of the rich and powerful Mary Sue!

- Description from Novelupdates