Ultimate Firepower

This world is not only what ordinary people are familiar with, but there is also an underground world that ordinary people will not have access to.
Government agents deal with troubles secretly, and killers hired by chaebols solve problems privately.
There are killers, mercenaries, arms dealers, and agents. There is the dark web that connects the world together, and there are also plutocrats who try to control everything with money.
Gao Yi broke into the underground world, and he was invincible in close combat and established his own field.
But there are guns in this world. Seven steps away, the gun is fast.
Within seven steps, the gun is accurate and fast.
Gao Yi's punch is fast within three steps.
Join if you can't beat him, Gao Yi chooses to have them all.
Want all of them, become the king of killers in the mercenary circle, the king of agents in the eyes of killers, the king of killers in the eyes of agents, and the king of intelligence in the eyes of arms dealers.
Until he is crowned king in the entire underground world, Gao Yi is the ultimate firepower.