You Were Supposed to Go Undercover, Not Loot the Entire Sect

[Refreshing article] + [No female protagonist] + [Decisive killing] + [Invincible at the same level in the early stage + Invincible by leapfrogging in the mid-term + Directly invincible in the late stage] Qin Mang traveled through time. Good news, this is a fantasy world where you can cultivate immortality. Bad news, I just got stabbed by the saintly senior sister I've had a crush on for more than 20 years. The original owner was an undercover agent of a top sect and had been a royal guard in the imperial court for nine years. From a low-level warrior to a thousand households, he is about to be promoted to a commander, marry Bai Fumei, and reach the pinnacle of life... As a result, he became cannon fodder for the sect's infighting. After nine years of sincerely feeding the dog and licking the dog, I ended up with nothing! Bite! The sword crit system has been activated! [Any attack you make will trigger a critical hit! Killing enemies can infinitely increase the critical strike multiplier! At the same time, panacea and magic weapon skills are randomly dropped...] Looking at the hole as big as a bowl in his heart, Qin Mang smiled. "Then there's nothing we can do." Since then, the world has welcomed the most unreasonable murderer. Zhengdao: "Please don't let him handle any more cases! Just because he trampled a few ants to death for Tian Xingdao, he killed us directly." The devil said: "We are devils! We are the villains! Why is he, a guard in uniform, more cruel than us?!" Immortal Dynasty: "Qin Mang is the sharpest knife of our Great Yan Immortal Dynasty, overseeing the world and slaying demons! Um... Can you take the knife off my neck?" Many years later, when Qin Mang split open the immortal gate with his sword, he looked at the bewildered immortals and gods and spread his hands helplessly. "I really didn't want to cause trouble. Who knew that the Immortal Sect was so fragile that it couldn't even block a million-fold critical strike?"