Great Ming: From the Start, I Saved Zhu Biao, and Old Zhu Went on a Killing Spree

[Dual-World Transmigration + Historical What-If + Ming Dynasty + Modern Firearms Overwhelm the Enemy + Ancestor Legacy]

Also known as: Zhu Yuanzhang Transmigrates to the Chongzhen Era to Keep the Ming Dynasty Alive for Ten Thousand Years!

Su Chen, a history major in the 21st century, unexpectedly awakens the [Ming Dynasty Dual-Transmigration System].

This door connects the Ming Dynasty's most prosperous year, Hongwu 25, with its most desperate year, Chongzhen 15.

The System's rules are simple:

1. Travel between two worlds: There is a cooldown, but he can still become the greatest cross-world trader!

2. Exchange national destiny: As long as he changes the Ming Dynasty's fortunes, he can expand the System's space and even unlock [Living-Organism Teleportation] privileges!

3. Overwhelming resources: He can exchange points at the store for flintlock guns, cannons, and high-yield sweet potatoes to arm the Ming Dynasty!

And so, the Ming Dynasty's whole outlook changed.

In Chongzhen 15: The Chongzhen Emperor said, "I have no money or food, and the rebels are about to march on the capital!"

Su Chen said, "Don't panic. Come with me. I'll take you to the Hongwu era to clean out your ancestor's treasury!"

In Hongwu 25: Zhu Yuanzhang said, "What? My Ming Dynasty fell? My worthless descendant hanged himself at Coal Hill?"

Su Chen said, "Don't worry, Old Zhu. The door is open. Go there yourself, bring the descendants of Lan Yu and Xu Da, and teach those rebels a lesson!"

When five hundred Napoleonic cannons are positioned at Shanhai Pass...