He transmigrated as 13-year-old Ying Zheng, and from the start, it was hell mode:
Lu Buwei held power, Lao Ai plotted rebellion, the Queen Dowager wanted him dead, and the Six States were waiting to laugh at him.
Fortunately, the sign-in System arrived.
Sign in at Xianyang Palace, and receive the Emperor's cultivation art, Ancestral Dragon Art.
Sign in at the Grand Ancestral Temple, and receive the Great Qin Fortune Cauldron, which can see through loyalty and treachery.
Sign in on the battlefield, and summon Bai Qi, the God of Death, to shoot Lao Ai dead with one arrow.
Sign in at Mount Tai, and activate the spiritual veins of the Nine Provinces, ushering in an age of cultivation for all.
Others struggle to cultivate, but I grow stronger just by signing in.
Sign in at Mount Li, and receive a ten-thousand-year spiritual vein.
Sign in at Penglai, and receive an elixir of immortality.
Sign in in the Celestial Court, and claim the throne as ruler of all worlds.
The Six States? Destroyed.
The Celestial Realm? Taken.
The myriad worlds? Subdued.
I, Ying Zheng, went from being the Ancestral Dragon of Great Qin to the Heavenly Emperor of the myriad worlds through sign-ins.
Wherever I sign in becomes my territory.