So I'm a Dragon, So What? - Game System - Chapter 45: Evil Grin!

Jiang He might have transmigrated to a world of Qi and martial arts, but the System that he got only provided him with… seeds.

He, since childhood, had followed the Foreigner to practice the Defying Heaven Art, entering the most secretive special forces and becoming a fearsome assassin that made others tremble at the mere mention of his name. After a single failure, he took early retirement, but he ended up as the personal bodyguard for a rich heiress, a school beauty. Accidentally provoking some mysterious Cultivators, he gradually unveiled a hidden world of Cultivation beyond the mortal realm...

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates