I might be the only gun user in the wizarding world, right?

A child paper who was killed by God's hand trembling, just like the plot of a graphic novel, got the opportunity to travel to a different world with magic and obtained an almost omnipotent system.
This is a good story, but when the weapons obtained by that child through the system are not magic staffs or cheats, but modern weapons and grenades, it will become a strange story !