Mitou Shoukan://Blood-Sign - Volume 8, Stage 02 - The Treasure Chest is in the Frozen Undersea World

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

A minus’ hand that fails every singer he put his hands on, Kang Yoon.

Han Yang never thought he would one day sell himself into a marriage with another man. He believed his life would be mundane but that man, named HeLian Qing, broke his pre-planned life. Parental debt, a child’s compensation, he had no chance whatsoever to resist, he has no ability to resist.

She, the prime minister’s daughter, was timid and cowardly. Because her engagement fell through, and her reputation was ruined, she was pressured to spill her own blood in the palace hall! Once again opening her eyes, the cowardice had vanished, replaced by coldness, causing others to be intimidated at first glance. Yet no one realized, she was not her.