Great Tang: Changle, I’m Your Brother-in-Law. Show Some Restraint

Xiao Rui, heir to a mysterious family of ancient martial artists, accidentally transmigrates to the early Tang dynasty and becomes the eldest son of Xiao Yu, Duke of Song. He has no interest in inheriting the family estate or becoming an official. He just wants to start a business and invent things, using all kinds of technology and methods to dominate the Great Tang and become the world's richest man. But the emperor takes a liking to him and grants him the hand of his eldest daughter in marriage, making him the foremost imperial son-in-law. As Xiao Rui grows stronger and more capable, his influence keeps expanding, and more and more people gather around him. Even Princess Changle, the emperor's most beloved daughter, is... Now Xiao Rui is in a real bind: It's over! Great Tang law allows an imperial son-in-law to marry only one woman. What is he supposed to do?