Feel free to take my ideas and use them.

It could be an interesting scenario if let's say in a parallel universe that King Sombra won during the episode The Crystal Empire, thus consuming the entire world with fear and hatred.

Would could that mean?

Perhaps a world filled with bitterness, slavery (concentration camps), and war (rivers run red with Pony blood and stuff), with only the odd few not completely consumed by fear and hatred.

A world under King Sombra rule only hope may be MLP Ponies from yet another parallel universe to liberate from tyranny under King Sombra.

King Sombra minions corrupted Ponies turned evil (much like Orcs) with red eyes or something that eat meat and other non corrupted rebellious Ponies that stand against King Sombra.