Necromancer Of The Shadows - Chapter 669 Eighth Floor

After dying from betrayal, Thomas reincarnates as Jolthar Kaelzhar, the neglected son of a powerful clan, just after his brothers kill him. With Jolthar's memories and the blessing of Qalena, Thomas vows to rise from his lowly position and claim power in his new life.

This novel is also known as Long Live the Mad Wife!

Daughter of the Feng Family, born a waste. Forced to marry a fool in an attempt to expel evil influences. When the first killer from the 21st century possessed this body, the sky and the earth surged. She was indifferent and cold-hearted but she let her guard down around him alone. She thought he was a pleasant sheep but didn’t expect him to be a gray wolf in disguise!

- Description from Novelupdates

A young farmer's son, Oscar, is content with living a peaceful life, but by fate's whim, he is found to have the potential to become something greater, an Exalt. A special class of humans who perform miraculous feats and lord over others. Despite his shortcoming and slow progress compared to the geniuses around him, Oscar holds determination as his shield and persistence as his blade. Who says that a person needs to be a genius?Who says that a person has to be a prodigy?With each heavy step, Oscar walks the path of an Exalt.

With a marriage contract forcefully done, he married her, and all she could do was comply, and resent him deeply for that and for all the following misunderstandings they faced.
However, it was already too late when she understood she actually loved him.