Genshin Impact: Supreme Justice of Teyvat - Chapter 3 - The Birth of the First Monster

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

Thanks to the Goddess, he was reincarnated into nobility!　That should have been great―― but the skill he got, 【Toxin Decomposition EX】 was simply too plain, and he was made fun of everyday at home……

Despite being the ruler of a nation, nobody was willing to marry the vicious man with a bloodlust.

A young boy genius, Suo Jia, is a water mage who dreams of being a warrior travelling the great and dangerous trade routes to find his lost father that set off on them before Suo Jia was born. Having to look after his sick mother, Suo Jia manages to find a way to solve all their problems, as well as make a name for himself. He gathers nobility, vast wealth, items of great power, knowledge lost to the ages, and exceptionally talented females around him as he plots and plans – preparing to set off on an epic journey that will go down in history as a new legend. However, will others that depend on his powers so much be willing to let him go on such a dangerous journey so easily?

- Description from Novelupdates