Every faction has a "If something happens they'd win" clause though. If all the Orks united for a WAAAAAGH! they'd win. If the Tyranid hive fleet actually arrived they'd win. If the necrons all awoke they'd win. If the Imperium stopped fucking around for five fucking minutes and got it's Divine Avatars together they'd win. I'm going to assume since I know nothing about thethaluikhain said:In 40k that is (or was) at most a temporary thing, sooner or later He would die and chaos would win.HellbirdIV said:The big difference is that they can't lose. The Chaos Gods of WH40K are kept in check by the Emperor's psionic powers
In GW more generally, it's hinted that Chaos could win whenever they wanted to, but a destroyed world/galaxy is no fun. So they give limited power to mortal champions and send them off, because it's more amusing than playing on literally god mode all the time. As such, they can't lose, the world only has a chance of surviving until they get bored with it, and it's only a chance even then.
Everything in 40k is pretty bad, it's usually torture, torture, killed, brainwashed, killed, tortured, killed. Sometimes by your own team. But that has all been said.
I'm going to go with the dark ones from Metro 2033. If you played the games you know them as the creepy looking ones that keep chasing you, not too scary. I read the book, and the description of the sheer inhumanness of them in the first few chapters is the only monster in my adult life to give me nightmares. I hope one day to actually continue reading it.
Also I didn't play much of the Resistance series before my PS3 died, but the Chimera. Wow. I mean, Grimsby is already a factory for soulless non-humans anyway, but still.