Toaru Majutsu no Index - Volume 1, Chapter 1: The Magician Lands on the Tower. FAIR,_Occasionally_GIRL.

Xiao Yu, who was a student from modern Earth, accidentally transports to another world and becomes the lord of a territory. Facing an unfavorable situation, he vows to take back his family business, build his new territory, kill all of those who covet his wealth, and dominate the world!

- Description from Novelupdates

He’s in the deepest part of Jianghu.

Keep your eyes wide open.

If you do not wish to get dragged into the abyss.

On a dark and windy night, he picked up a beautiful, charming, sexy and enchanting beauty, and his life was filled with ups and downs...

Yin Li was born with a pure Yin body. He possessed the body of a male but the fate of a female, his Yin and Yan energies fully inverted. Because of this, his family’s old ancestors claimed he wouldn’t be able to live past twenty years of age.

To prolong his life, his parents fostered a furnace whose energy he could harvest to nurture his own.

As Yin Li looked at the frail and delicately charming boy in front of him, he felt his heart stir with compassion.

The Heavenly Path is carried through reincarnation, life and death are decided by fate.

He couldn’t simply ruin this pitiful child for the sake of his own selfish interests. Instead, he kept the small boy at his side, spoiling him and raising him as his trusted aide.

He truly believed they shared a master and servant’s pure and honest affection, not at all realizing that that wicked boy had been rotten from the start. The delicately charming small boy who was spoiled day and night only ever thought about two things:

1. Why hasn’t master bestowed his favour on me yet?

2. Just how can I climb into master’s bed?

- Description from Novelupdates