Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 445 - 444: Big Fishing Contest

A Japanese salary man was reincarnated in a different world with swords and magic. He reincarnated into the family of a powerful noble. One day when he became twelve years old, he was suddenly summoned by his father.

「 I do not mind whether it is a woman in the town or a maid in our house, learn about women.」

Having gained the permission of his father, he uses his power as a noble to have his way with women.

This novel is also known as Master Fu's Mysterious Darling Wife

She is the The Young Miss of Military family Shen, her face is peerless, her temperament is cold, and she is her family’s treasure, but isn’t accepted as one’s child by her mother;

He is The Sole Heir to the top giant Fu Family, his power is unparalleled, indifferent high-born, the captain of the mysterious military force, and the youngest commander-in-chief.

Because of her grandmother’s wishes, she married him at lightning speed. She thought that it was a marriage that she needed, but she didn’t expect to be greeted with his extreme pampering.

- Description from Novelupdates

The world had shown Baines every possible lesson it could teach; from familial love, joy, and peace to hate, rage, betrayal, and pain.He got detached from his family by the wimps of others.But, before he began his journey to find them, he was forced to witness that scene that haunted him once more. The destruction of his home.He was about to give up on life when an unforeseen opportunity presented itself.There, he vowed, “The world will bleed for what it has done to me.”Using the greatest collections gathered by his ancestors, he set out on the thorny path to revenge.Little did he know, the result of his actions followed other cascading events that then threatened his world.Does he refuse to help the world because of the pain it had caused him? Or, will he join in the destruction?