I Was Banished from Heaven, Now I'm the Demon King's Stepdad?! - Chapter 26 – “The Girl Who Shouldn’t Exist

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move:

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

He rose from abjection and achieved eternity in glory.
He embraced the prettiest beauties and killed the strongest opponents.
He was able to shift the clouds into rain and cover the sky with one hand.
He could overrun the entire world and go anywhere as he pleased.
He pacified wars and held the world in awe.
He was matchless in the world.
However, his hair turned white overnight for his beloved woman and he was on the verge of death.
He was surrounded by enemies who were trying to take his life.
He struggled his way to become mighty and fought for everything he cherished.
For this age, he was the only king of the Dark World.
His name was a byword for might.
As a man living in the world, his only ideal was to pursue brilliance.

She is the daughter of an Alpha whose family had conquered the last demon wolf in Illyria.Esmeray is born into the prestigious Alpha family, known as the Montague. But after her father's untimely death, her life becomes a nightmare of abuse at the hands of her cruel stepmother and stepbrother, who torment her for lacking a wolf.Desperate for salvation, she dreams of a mate who would come and rescue her from the cruelty of her pack. When he finally arrived, her hopes were shattered, for he had only come to reject her.Her only connection to her family's proud heritage is her striking blue hair, a sacred legacy from her ancestors. But in a desperate bid for freedom, Esmeray cuts her hair to escape being sold to a rogue.Her daring action pushes her to the precipice of death, unwittingly awakening a powerful demon wolf, imprisoned for 15 long years. This Alpha demon, who has yearned revenge and bloodthirst, is instantly drawn to Esmeray the moment he senses her, and he is determined to keep her at his side at all cost.In the world of wolves, the hunt is everything — and he has found a prey worth chasing.