Another idea I had for those who like "Corruption of Champions".

Title: Corruption of MLP

Main characters: The Main Six & Spike.

Genre: Alternate Universe, Anthro, Dark, Adventure.

Premise:When odd creatures start attacking Ponyville from the Everfree forest, the main six (plus Spike) go to investigate. Upon venturing deep into the forest they find the portal hwere all the creature's are spawning from, they try to fight them off but end up getting sucked into the portal, sending them to the cursed Demon Realm!

Twilight ends up in the forest.
Rarity ends up near the lake.
Rainbow Dash ends up in the desert.
Fluttershy ends up in the mountains.
Applejack ends up in the plains.
Pinkie ends up in the swamp.
Spike's location remains unknown...

Separated and lost, they must now find a way to survive their new environment...and try to resist the temptation of this world...