This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / The Punisher
Punisher POV. Its main villain is a case of Body Horror thanks to toxic waste, and when he bites a pregnant woman, she gives birth to mutated a baby that slaughters it way out of a hospital and has to be confronted in the sewers below.
Frank Castle's own death during the Dark Reign also counts. There are few sequences in the Marvel universe that so effectively and blatantly present the risks of Bullying The Dragon, as Punisher's stubbornness and arsenal are pitted against the regenerating Daken, who proves just how useless they are. Daken starts by shooting him and blowing him up with grenades, seemingly just for kicks. Then the mutant closes to hand to hand range, where he pummels Punisher mercilessly, breaks his leg, slices his throat open, hacks off a limb, and, finally bored of it all, cuts him into pieces with the ease of an industrial meat slicer.
The Punisher is this incarnate. Morality is below him, sanity, health, the law, nothing matters to him except killing criminals. Frank Castle loses everything, and then loses himself. The Punisher is not anything human anymore, he's a weapon pointed directly at the criminal underworld.