Equestria's freaky pseudo-invasion

"All right, ladies, let's show him what friendship can do !"

This was it. Discord ... was beaten. By six mares. With ROCKS. He couldn't accept it. He just couldn't. All of these years, during which his seal was slowly weakening ... all of this waiting, his long patience, all of it, was it ... a waste ? His body was turning to stone. He had to act, quick. So he concentrated all of his powers in his mouth ... and spat. He would've entered the Guiness book of world records for that spit, if it existed in Equestria. A sphere of pure chaotic energy was sent towards the Evrefree forest. Nopony noticed it. Right after that, the transformation was complete. He was now sealed again, for Celestia knows how long. But he was satisfied.

A wave of pure chaos was felt by every living creature of the Everfree. Some felt a shiver, some remained calm, others decided to hide. But it was there : a massive, red nebula, in the middle of the forest. Using the power of science, it linked Equestria with a dimension nopony wanted to see with their own eyes : Tartarus. But Tartarus wasn't just a little chunk of space. It was made of tons of individual hells, for each creature that the Gods banned from the overworld. This specific portal in the Everfree directly led to the hell corresponding to a violent dimension, struck by war. However, it wasn't a massive butchery of thousands of men. There were only eighteen fighters, really, duplicated, cloned, again and again. But sometimes, RESPAWN ( Reanimation Emulation Software for Preserving Authorized Weaponery and Neurons ) messed up, influencing either the capacities or the psychology of the clones. That said, those who were judged too dangerous for the world, were sent to Tartarus.

They were called the freaks, and Celestia knows what happens when they're unleashed.