Darkstalkers/Nightmare Fuel

This being a series that has monsters and supernatural entities as fighters, it should serve as no surprise that there's some legitimately terrifying stuff in this series.

• The "Fetus of God" stage from the third game. Spoilered for the faint of heart: it's a rather realistic literal Womb Level, with a giant horned fetus with no skin, just covered by muscles and veins, in the background. It awakens and stares at you while pulsating at the end of the match.
• Most of Jedah's moves involve extremely bloody self-mutilation, and one of his counters even involves decapitating himself and growing his head right back after spraying his blood all over the opponent. Also his laughter.
• The Midnight Bliss move from Demitri can change guys to hot girls, and hot girls to hotter girls in most cases. But it's particularly disturbing to see that right afterwards, Demitri picks them up and literally sucks the life and blood out of them, leaving the girls a shriveled, skeletal corpse. The fact they explode and return to their normal forms right after can offset this, but the brief images are still a little disturbing, to say the least.
  • In addition, after transforming the unfortunate victim, Demitri takes on his true form as he drains them. Said form is that of a horrific humanoid gargoyle/bat hybrid.