I Am Engaged in Arms Production in the Tang Dynasty

Lu Fan, a student at the Weapons Academy, accidentally traveled to the Tang Dynasty and rescued Li Shimin at the beginning. There was an assassin attack. Lu Fan said, "Your Highness, please be patient and come back as soon as you get down." Bang, Lu Fan threw a homemade grenade, and the three top assassins stared blankly: What kind of hidden weapon is this? So... Amazing, we are all first-class masters... When enemy troops invaded, Lu Fan said, "Your Highness, our artillery has been developed successfully. Let's go and test its power." Boom, boom, boom. After a burst of fierce artillery fire, the enemy soldiers jumped on their backs and fled: What kind of weapon is this? Even our iron pagodas can't stop... Multiple female protagonists, a bit of martial arts, no system.