king Sombra has taken his rightful throne, he has crushed his enemies and heard the lamentation of their mares, but a king needs heirs, Sombra decides the mane six are the mares to bare them, whether they want to or not. Top it all of with an unknowable cyclopean horror from the sightless pit and you have a monarch that Equestria won't soon forget.

warning contains, struggle-snuggles , gore, death, estrus, impregnation, f-bombs, and a bunch of other filthy, filthy prose.
basically, this is the kind of fanfic which makes you feel like less of a person after reading it.