Great Qin: Kidnapping the First Emperor from the Start

He transmigrated to Great Qin and became the lord of an island! He trained a new army, developed gunpowder, and gathered talented people from far and wide. Su Feng was preparing to rebel against Great Qin! After a storm, two shipwreck survivors appeared on his island. One of them kept claiming to be Great Qin's First Emperor, Zhao Ying Zheng. Su Feng was furious. How could someone show off even more than him? That wouldn't do! Throw him in the dungeon and make him eat prison food! Three months later, when Su Feng heard that Qin troops were preparing to land on the island, he panicked! This guy really was Ying Zheng! He had thrown Qin Shi Huang in the dungeon, fed him pig fodder, and made him squat over a flush toilet! It's over! What should he do? This is urgent! Anyone there? Save me...