Let you go to the capital as a hostage, and then you will ascend the throne as emperor?

[Powerful plot + multiple heroines + exciting story + hegemony + farming] Wei Ran travels back in time and becomes a substitute for the crown prince of a different surname. The real crown prince is enjoying his life in his fiefdom, while he is a hostage in the capital? If so, then I will take his place and become the real crown prince. Emperor Dali: Crown Prince Wei, I will marry the third princess to you! The real crown prince's aunt: You may be my fake nephew, but I am your real wife! The real crown prince: Father, this imposter stole my princess and aunt, I want my identity back! The king of a different surname: My son, it's too late. He destroyed my 300,000-man army...