A Lowly Guard in the Celestial Prison: My Techniques Level Up to Max Automatically

[Heavenly Prison + System + Overpowered Protagonist + Decisive Killer + Cautious Survival]

Chen Chang'an transmigrates to the Great Wilderness and becomes a lowly jailer in Cell C-1 of the Heavenly Prison. This is a dangerous world teeming with demons and countless mighty beings. He only wants to keep his head down and survive, but unexpectedly awakens the [God-Tier Epiphany System].

Whatever the technique, one look is enough to master it completely! The incomplete, common "Savage Bull Fist"? Epiphany! It evolves into [Mountain-Moving, Sea-Filling Force]! The evil cultivators' fragmentary "Energy-Absorbing Art"? Epiphany! He deduces it into [Great Devouring Art]! A sword mark left by some Sword Immortal? Epiphany! He comprehends [Ten Thousand Swords as One]!

Years later, the Great Sage of the demon race leads ten million demon soldiers in an attack on the imperial capital of the Great Wilderness. Just as humanity falls into despair, the demon army storms the Heavenly Prison, only to see a young man in a jailer's uniform picking his teeth with a toothpick.

Chen Chang'an: "Who told you to interrupt my nap?"

One punch, and ten million demon soldiers vanish into dust!

The Great Sage falls to his knees: "Father, I came to the wrong door..."