Rakshasa Gate: Nine Ghosts Cover the Sky

In the chaos of the world, human science and technology developed at a rapid pace until an explosion in the 21st century caused a firearms developer from a military factory to travel to a world belonging to the Summoner. He gave birth to a son named Song Yuqi with a local woman, and was taught how to make firearms. And met eight other people to form a team called Jiugui. And carry forward weapons that do not belong to this world to the world... Disclaimer: This book is not about time travel. The time travel mentioned here is just a foreshadowing. You can ignore the bad introduction