The warbands and tribes who follow Khorne exclusively. No devotee of the Blood God knows full loyalty to another, for when all is said and done, all mortals are merely skulls yet to be claimed in Khorne’s name. A common belief among them is that a day gone by without a death in Khorne's name is a day wasted. Because of this, the greatest champions of the Blood God bind their armies together not through common cause, but with the shackles of hate.
The warriors of Khorne band together with others of their kind in order to better wreak destruction upon their foes. However, even within the tribal structures of the Bloodreavers and the strange, pseudo-daemonic packs of the Wrathmongers, cooperation lasts only so long as there are sufficient foes against whom to win personal glory, or if they believe Khorne has brought them together for a greater purpose. When a Mighty Lord of Khorne gathers a warband of Bloodbound around him, this same phenomenon is writ large. Each band of Bloodbound eyes their fellows with open hostility, waiting for any excuse to do violence in Khorne’s name. By finding sufficiently challenging foes to slaughter, the lord hold his frenzied followers together, giving them common purpose beyond tearing each other apart. Only the greatest champions of Khorne can hold their followers together for more than a few battles or campaigns.
The Bloodbound tribes have their origin in the realm of Aqshy, when numerous warring tribes decided to settle their disputes with a vast contest of champions known as the Red Feast. However, the whole tournament was orchestrated as a ruse, upon the death of the eight hundredth and eighty-eighth champion, the Daemons of Khorne were unleashed unto the world. Some of the tribes started worshipping Khorne in hopes that they would not be among the slaughtered, although others willingly joined in order to sate their bloodlust. The most notable champion of the Red Feast was Korghos Khul, who eventually became the greatest Mighty Lord of Khorne in the Mortal Realms.
As the Age of Chaos raged on, howling hordes of Bloodbound burst from the Eightpoints, descending upon the Mortal Realms at the head of the Chaotic hosts. With Sigmar’s alliance in tatters and the God-King’s forces locked in a fruitless war against Nagash, the people of the realms were forced to look to their own defense. Though they brought all sorts of monsters, weapons and magic to bear, with the Chaos God Khorne in ascendance the Bloodbound were bolstered and swept away most opposition.
With the servants of the other dark gods close on their heels, the Bloodbound smashed their foes defences asunder without a second thought. Gates crashed down, cities burned in hellish pyres, corpses piled higher and higher until blood-soaked mountains of carrion loomed over the land. And so it continued, for years, then decades, then centuries, with no end in sight. Civilisations beyond number fell beneath the axes of Khorne’s chosen. Time and again some proud chieftain or shining hero declared himself the scourge of these rampaging murderers. Time and again, his skull found its place at the Blood God’s feet. So terrible were the conquests of the Bloodbound that Khorne rose to prominence amongst the gods, and even his dark brothers shuddered at his might.
The Bloodbound quickly grew bored of their unopposed victory. Having destroyed all that opposed them in the Age of Chaos, they were forced to gather skulls by hunting down weak refugee tribes or slaying their own. So it was that the arrival of the Stormcast Eternals was seen as a blessing in disguise, for they at last had found opponents strong enough to challenge them.