Nan Yi and Nan Er are Iron Golems; currently, no firearms or weapons can harm them. This means that in this world, Nan Yi and Nan Er are effectively invincible. With these two treasures at his disposal, Nan Yu has nothing to worry about. It really just comes down to him deciding whether to kill the entire group or leave one alive.
Nan Yu pulled his head back, hid his body behind a large rock, and began calling the system in his mind. "System, I want to bring Nan Yi and Nan Er into my world. How do I do that?"
"Each Iron Golem brought into the real world requires a deduction of 100 Aura Value points. Bringing both Nan Yi and Nan Er into the real world will cost a total of 200 Aura Value points. However, I must remind the host: once an Iron Golem leaves the System Space, it cannot re-enter."
Chapter 177