This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / X-Men Origins: Wolverine
As Victor was chasing down young Cyclops, he accidentally emits an enormous energy blast that tears upward all the way through the roof of the school. Let's just hope nobody was injured or incinerated by it.
One from the video game. As Logan slices enemies with his claws, their screams of pain include frantic apologies, shock at all of the blood, and more.
Partly Fridge Horror. When Victor stops Kayla's car, as he advances towards her, he lets his claws rest on the hood of the car, and they tear through it as he drags his hand over it as if it was made of butter than metal. Now imagine such sharp claws on flesh