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Nightmare Fuel: God of War
You'd think that running around as pretty much gaming's ultimate badass, who stumbles upon Moment Of Awesomes with every step, and hacked his way out of hell three times, would excuse one from this. You'd be dead wrong. Ares decides to Mind Rape Kratos by having him fall to the same church where he slaughtered his family, with them still alive in it, and pale(r) copies of Kratos emerging from holes in the ground to do them in. Fighting against these true monsters as they seem to spawn endlessly, your family screaming in terror, the numbers overwhelming you as the church begins to break apart in the void. At the end, when after you have defended them to your last, your chains are ripped from your body, and used to kill them anyway.
The hydra's roar in the first game. Jesus Christ.
In the first God Of War, in order to proceed, Kratos must "escort" a trapped, live, innocent soldier to a room, where he is sacrificed to open a door, which is bad enough, in and of itself.
The worst part is he's begging for his life the whole time and his pleas get more and more frantic and desperate the further you progress. When you finally reach the chamber, he's crying out for the gods to save him only to be burned alive shortly afterwards. Curiously, the preceding scene seems to imply that even Kratos isn't happy about having to do this.
Strangely, sometimes the live soldier is replaced with a trapped zombie warrior/cannon fodder enemy and Kratos SMILES seeing this, knowing what he has to do.
For bonus horror, the soldier in question is voiced by none other than Rob Paulsen. That's right, Pinky/[[Western Animation/Animaniacs Yakko]]/Raphael is begging you for mercy while you (probably a late teen or twenty-something at the time of the game's release) kill your own childhood.
Clotho, the Fate who spins the threads of life, from God Of War II is creepy. For one thing, her lair is dark and ominous, as opposed to the rest of the Temple of the Fates, which is bright and majestic. Plus, her lair is strewn about with threads in a way that is reminiscent of cobwebs. As for Clotho herself, she's so massive she even makes Jabba the Hutt look like Calista Flockheart, and her skin is a sickly dark gray and zombie-like. To top it all off, she has multiple breasts and spindly little arms sticking out of her body. And last but not least, there's that little speech she makes when you first see her: "It is through my threads that all life is born. You must not tamper with destiny, Kratos. You will destroy everything!" Kratos may not be afraid of anything, but we're not so lucky.
Kratos himself. That this single petulant, Psychopathic Man Child is willing to essentially destroy reality itself purely in a fit of pique is bad enough. The cruelties he inflicts on innocents and monsters alike are the stuff of nightmares. That you have to play him is worse.
Ghost Of Sparta give us Scylla: Let's see: a giant part-shark part-squid part-narwhal part-crab monster which lurks in the water and has a penchant for sneak attacks and will chase Kratos even in an active volcano to kill him. The part where you fall into the water and the first thing you see is this giant monster rushing towards you with gaping maws open is quite scary.
Hades. Both the character in God of War 3 and the place itself in the first game: navigate through platforms made of flesh, bones and blood.
Charybdis. There is nothing more frightening than seeing a monster in the pitch black of the ocean swimming towards you with its mouth ready to devour you.
Hell, most of the bosses in Ascension, which could easily be renamed "Body Horror parade". Castor and Pollux are reimagined as siamese twin mutants, instead of zombies the Furies use parasitical arthropods that hideously mutate their victims, the Furies themselves. It's like someone decided to remake The Thing (1982) in classical Greece.
Actually, Pollux is made to look like Kuato. The game's achievement for killing him is called "QUAID!!!"
You know the horrible brutality Kratos inflicts on his enemies? The horrible part is that almost all of them deserved it, especially the bosses. If they arent horrendous, rampaging mindless monsters, theyre cruel, petty gods or arrogant "heroes". The worst part of the world of God Of War isnt what Kratos turned it into, its that everyone he killed along the way absolutely refused to accept any responsibility for what happened. Ares, Zeus, The Fates, the Furies, all of them are just as responsible as Kratos.