MTL - This Ninja is Obviously Not Strong, But He Kills Too Much - Chapter 18 Xiaoye is the future 5th generation

Ever since he was little, Xi Jia’s yin energy was strong, and every day he saw ghosts and ran into ghosts. One day, he accidentally broke the protection amulet. Celestial Master Ye Jingzhi happened to pass by and helped. Are ghost catching Celestial Masters all legit masters? WeChat official accounts, Taobao online shops, looking at gossip tabloids every day. Since then, Xi Jia has refreshed the lower limit again and again, and met a group of completely unreliable Celestial Masters. Binding spirits, doppelgängers, the Mausoleum of the First Qin Emperor, the ghost market of Poyang… The door to a new world is slowly opening.

Set in an urban city with supernatural elements, this is a love story between Xi Jia, who has a body of extreme yin, and Celestial Master Ye Jingzhi, nicknamed the King of Hell. The seemingly weak Xi Jia, in actuality, can rip apart ghosts with bare hands; the seemingly cold Ye Jingzhi, in actuality, is shy and gentle. A marriage contract binds the fate of two people together. See how the two people overturn the heavens in the gossipy and wacky metaphysical world.

- Description from Novelupdates

The young lord of a small and weak country saves a dragon beside the sea one day.

Emperor Zi Yu used 5 strikes of his axe to split mountains and unify everyone underneath the heavens. He partitioned the land into 9 areas, thus establishing the Nine Cauldrons which eventually became known as the 9 prefectures.