Iron Guard of the Ming Dynasty: Wang Zhi, a Man with a Different Surname Who Travels Through Time

The protagonist traveled through time and became an auxiliary soldier of the border army. He survived the remnants of the "Battle of Daling River" and used the "leverage principle to improve the trebuchet" and "gunpowder ratio optimization" to repel a small group of rear Jin cavalry. He was noticed by the guerrilla general Zhao Zhijiao and promoted to "Military Industry Praise Painting". Respect the historical framework, reject "brainless cool writing", and show the difficulty and significance of technology promoting social change.