In archaic times, sabelhests and similar creatures were seen all throughout Voweg Turr, a land of near-mythical status if only for the incredible blasts of sound it would trap. Formed in the shape of a towering bowl, the scarps and flatlands alike of Voweg Turr were deafening to stand within, as the shape of the land captured huge torrents of wind from the sea that could only circle its walls until they died down. Most native creatures of this land were deaf, and communicated in low, vibrating hums and bellows.
Though in most circumstances they acted alongside the natural roles of any other horse, sabelhests had one rather specific purpose within their territory, which was to ward off creatures that did not belong within their mortal plane.
A sabelhest would never run from a revenant, instead charging to face them head on and forcibly eject such creatures from the living realm to wander between the many halls of the dead. With its affinity towards expulsive magic, a sabelhest is far from helpless before the undead. For many eras following the presence of these animals, Voweg Turr was a realm that seldom fell under serious danger of the undead, ghosts usually appearing only in response to disturbed graves or purposeful dark magics. Occasionally a small wave of draug might emerge from the sea, washed up onto the shores from other lands - wander as they might, sooner or later they would have to contend with the herds.
Long ago it was said that a sabelhest would come into being when a wild herd grazed above the site of a great natural disaster, and that where many animals entered, they would leave as only one, empowered by the remnants of the site's natural magics. While sabelhests do possess some degree of magic, it's more easily observed that they reproduce in the same way that any other animal would - so assuming that an animal could even be produced in such an abnormal manner, this story would certainly not be true for every sabelhest out there.
In the age of conquest, this is a story that is seldom repeated. Branded as the death-faced spawn of evil magics, sabelhests have been hunted into scarcity, the warriors of numerous foreign lands having quickly decreed them to be a formidable threat and demanding to put them down before they can bring foul magics to new lands. Unfortunately, a sabelhest's expulsive magic holds no command over the living - thus they have become few, and Voweg Turr has been lost to the undead blight.
Though fewer, there are a number of countries that do not view sabelhests as dark creatures which have helped them to expand into the wildernesses of their own lands. Mostly left to their own devices in the wilds.. as long as they stay within the right borders, anyway.. sabelhests are occasionally ridden in the more accepting countries, and when properly trained, they make for as obedient a steed as any other horse. Riders beware, however; though its horns are widely-set enough to allow its back to be saddled, it would take but a quick turn of the beast's head to forcibly dismount its smaller companion.
TLDR; ...If I knew how to summarize there wouldn't be this massive wall of text.
I used a combination of these images as reference for the fur shine and leg anatomy.
I'm quitting Chickensmoothie as of May 2018 so I won't be able to answer any questions on this species, but please rest assured that I will not be coming after anyone for using this.
This is a 100% open species and I give anyone who cares to use it full permission to use it however they want. Onsite, offsite, drawing, adoptables, free, sales, redo the lines, tweak the lore, make your own subspecies for all I care. Whatever it is you want to do with this, go nuts. As far as I'm concerned, sabels are public domain. Have fun.