Earthdawn/YMMV


 * High Octane Nightmare Fuel and Eldritch Abomination together again! Horrors are a GM's wet dream, really: I can torment your character for no reason, for as long as I want, and the only way to make it stop is to kill an insanely powerful creature from another dimension. Each Horror is different, each with a nastier assortment of powers than the last.
 * One of the fiction books, Lost Kaer, would make a great horror movie: a Horror has inflitrated the kaer of the title and is enslaving the minds of the inhabitants one by one.
 * The fate of Wyrmwood/Bloodwood and its inhabitants probably also qualifies as High Octane Nightmare Fuel.