Daqin: I Bring Technology to Create a Dynasty

Traveling through the Qin Dynasty but landing on a desert island? Fortunately, I have the system in hand so I don't panic at all! A few years later, Ying Zheng unified the six countries and patrolled the east, but unexpectedly discovered an island where immortals existed! However, Ying Zheng, who landed on the island in search of immortals, encountered things that shattered his outlook one after another!