The demonic brethren known far and wide as the Serpent Riders were at one point in time the chief scourge of the Heretic/Hexen universe, threatening multiple realms with their black magic and nigh-insurmountable armies. The worlds of Parthoris, Cronos, and Thyrion all suffered in turn under the merciless cruelty of one of the three Riders, with each one being brought close to the brink of ruination. The exact impetus for the Riders' destructive motives was unclear, as was the source of their control over dimensional travel, but it was known that each of them wished only to dominate, or, barring that, to destroy all that which could not be dominated. Each one operated independently throughout the series, though their goals were one and the same: to control, enslave, or kill every being in the known universe. From youngest to eldest, the Riders were named D'Sparil, Korax, and Eidolon, and the comparative power of each Rider within the trinity roughly corresponded to their age.
Despite the immense power of the three, the heroic actions of a small number of adventurers thwarted the machinations of the Serpent Riders' brotherhood on each of the worlds that they attempted to possess. Though their threat ostensibly ended when the last Rider, Eidolon, was slain, not long thereafter a dark mage named Praevus attempted to gather and merge the souls of the Serpent Riders with his own, which would have made him exponentially more powerful than they had been. He was fortunately prevented from achieving this end, but the fact that Praevus had devised a means to harness the Serpent Riders' souls left some to believe that the threat of the Serpent Riders would never truly pass, as those with ill intent might try to resurrect their former might at some future date.
The primary icon of the Serpent Riders, which is featured prominently throughout the series, is the crossed trident. The Riders' followers are often depicted wearing the symbol, and it also figures into the architecture of each of the games. Curiously enough, in Heretic II the sign also appears emblazoned upon Morcalavin's minions and the walls of his abode, though it is never explicitly stated that he is affiliated with the Serpent Riders. The only clue as to why this might be is contained within the game's preamble, which states that while traveling the Outer Worlds Corvus was shocked to discover "how widespread the taint of the Serpent Riders really was." Since it is never really explained in the game's fiction exactly why the failed Ritual of Ascension drove Morcalavin to commit the atrocities he did, the influence of the Riders' corruption can't be ruled out.
|The youngest and least powerful of the Riders, and the only one shown to have actually ridden a serpent, D'Sparil was charged with conquering the realm of Parthoris. His coming was swift and deadly, as he opened World Ripples in each of Parthoris' eight major cities, allowing his armies to spill forth unchecked. Of the five main races of the world, four surrendered to D'Sparil before day's end, and only one of the eight cities he had attacked, Silverspring, was able to mount a proper defense. Having noticed on the eve of D'Sparil's arrival a sudden ominous change in the stars, the Sidhe of Silverspring prepared themselves for the worst. Their city would ultimately fall as with the rest, but some of the Sidhe were able to escape the city's destruction. While the four conquered races of Parthoris were subjected to D'Sparil's intoxicating influence, eventually coming to willingly accept him as their lord and ruler, the Sidhe maintained their minds, though they still lived under the long shadow cast by the Serpent Rider. Most Sidhe cowered in fear as the demise of their people drew ever closer, though one by the name of Corvus, whose spirit had not yet been broken, vowed to do everything within his power to avenge the atrocities visited upon his people. He eventually fought his way to D'Sparil himself, defeating him in single combat. With his dying breath, D'Sparil curses Corvus to walk the Outer Worlds forever.|
|Whilst his younger brother struggled to pacify Parthoris, Korax, the middle brother both in terms of age and power, set his sights on Cronos, a human world where magic is strictly controlled. Ruled by the Legion, the Arcanum, and the Church, a triune system of government which dictates military, magical, and spiritual matters respectively, daily life in Cronos is inexorably tied to the interaction of these three organizations. Using greed and lust for power to his advantage, Korax seduced the leaders of each house, Zedek, Marshal of the Legion, Menelkir, Arch-Mage of the Arcanum, and Traductus, Grand Cleric of the Church, promising them each unfathomable power over their fellow man. Only one member of each house escaped the insidious influence granted their leaders by Korax: Baratus of the Legion, Daedolon of the Arcanum, and Parias of the Church. Outnumbered but not disheartened, the three resolved to kill their former masters, now little more than puppets of Korax, so that they might loosen Korax's grip on Cronos long enough to challenge the demon lord himself. Though the trials were many, and though Korax possessed even greater power than D'Sparil, the quest of the three heroes was successful in liberating Cronos from its heartless leaders, and when all was said and done yet another of the accursed Serpent Riders lay dead at the hand of mere men.|
|Eidolon, the eldest of his kin and unrivaled in his strength, was most known for his conquest of the realm of Thyrion. Heralded by a rain of fire and brimstone, Eidolon's coming was as sudden as it was brutal, as he goaded his vile armies against the fearful citizenry who scarcely believed such an evil existed, let alone marched toward their doorstep. Being as woefully underprepared as they were, the nations of man fell quickly, and before an entire day had passed all four of the continents of Thyrion had surrendered to the forces of Eidolon. As absolute as his victory was, Eidolon was not without caution. Realizing the fate that befell his brothers D'Sparil and Korax, he established one of his generals, the Four Horsemen of the Apocalypse, on each of Thyrion's continents. The Horsemen would not only act as proxy rulers, ensuring that his subjects would remain subservient, but also his personal line of defense against assassination, as he could only be confronted personally after each of his subordinates had been dispatched. After a long and horrific year under the tyranny of Eidolon, four heroes emerged, one from each continent, who challenged and overcame his champions. Without his four lieutenants protecting him, Eidolon soon found himself under siege in his own stronghold, and in spite of the terrible magics he commanded, he was slain, thus ending the reign of the Serpent Riders.|