You Told Me to Build the Great Wall, So Why Did I Wipe Out the Xiongnu?

Good news: Zhu Quan transmigrated to the Great Qian dynasty and became the eldest prince, first in line to inherit the throne! Bad news: The Great Qian emperor blindly trusted the wicked empress and wanted to make his second prince the heir, sending Zhu Quan to the northern frontier to build the Great Wall and fight the Xiongnu! Good news: After being exiled to the northern frontier, Zhu Quan unexpectedly awakened a Famous General Summoning System and summoned an SSS-rank army, the Xiliang Iron Cavalry, from the start! Bad news: What a disastrous start! More than ten thousand Xiongnu horsemen descended silently, completely surrounding Zhu Quan's city before he even had time to react! The Xiliang Iron Cavalry had yet to arrive, and the envoy Zhu Quan sent out was being hunted down. The eldest prince, Zhu Quan, was in grave danger!