Sailor Moon/Nightmare Fuel


 * Sailor Moon does not disappoint in this regard, especially in the S and Stars seasons, what with, among other things, Kaolinite's Daimons, who activate with the intended victim touching a harmless object with the egg hidden inside it, the Mass Sacrifice at Mugen Gakuen, and the wiping off of 99,9% of the World Population Galaxia does before the Final Battle. And that's just the anime...
 * Usagi hallucinating Mamoru's rotting skeleton in the manga.
 * In the SuperS arc in the manga, the main villain Queen Nehelenia forces everyone to have nightmares. Sailor Venus dreams that she finds Sailor Moon's skeleton with decomposing skin still clinging on.
 * In the second arc, Koan from the Black Moon Clan sets a little girl on fire for NO REASON.