I Transmigrated as a Prince, and They Begged Me to Become Emperor

Zhou Yan transmigrated into the body of the despised Sixth Prince, who was not the emperor's biological son. A bloodline test nearly exposed the truth. Then he got the worst System in history: completely useless, but always there for company. He was banished to a desolate fief, surrounded by enemy nations watching him like hawks. Using the knowledge he had gained in the modern world, he built industries and manufactured guns and cannons, putting himself far ahead of everyone else. When barbarian outsiders invaded and the corrupt court proved incapable of resisting them, the emperor had no choice but to seek help from the prince he had once despised most. Zhou Yan reluctantly accepted the throne and led his army against the invaders to defend his homeland. He reformed the government, developed the economy, and used an iron fist to restore order at court and eliminate corrupt officials, building an entirely new nation.