The Will of Demons
Both Horazon and Bartuc were equally powerful and ambitious, and both were fascinated by the power one could obtain through the practice of Demonic Magic. Horazon viewed demons as a great source of power and felt that in order to use that power best, a magic-user must harness a demon and bend it to their will. Horazon's ideology was in contrast to Bartuc, who advocated allying with the Burning Hells to best learn the demons' secrets.
Horazon and Bartuc lived in a time after the Sin War; when the Vizjerei were engaged in such reckless summoning of demonic forces that caught the attention of the other Mage Clans. When the other clans tried to assassinate some Vizjerei summoners and the Vizjerei responded in kind, the result was the Mage Clan Wars.
The Mage Clan Wars
The Mage Clan Wars were short but devastating. Pushed to the brink, the Vizjerei unleashed demons on their foes. The plan worked, and the tides of the war turned, as the Vizjerei pushed the other clans back to the ancient city of Viz-jun. Horazon however, had grown concerned. Bartuc had since gained the epithet "Warlord of Blood" and lived up to that name, slaughtering his foes and summoning demons en masse. He realized that even if the Vizjerei won the war, there would soon be nothing of civilization left, bar enslavement to Hell. However, the Vizjerei Ruling Council dismissed Bartuc for his acts of depravity. By this point, the views of Horazon and Bartuc on demons had turned into opposing philosophies, and thus a great schism split the ranks of the clan. Thus, the Vizjerei engaged in the civil war and after many hard-fought battles, Bartuc and his faction gained the upper hand. Thus, he turned his attention to conquering Viz-jun. Only then did Horazon resolve to confront his brother.
At the end of all things, the brothers realized that Hell had played them for fools, yet still they battled. By the end of the battle, Horazon stood victorious and Bartuc lay dead, yet at the cost of Viz-jun and the casualties, its destruction resulted in.
The Armor of Bartuc
Horazon and his fellow mages were unable to destroy Bartuc's corpse, as his armour protected him even after death. That he had failed to cover his throat properly was the reason he had been able to be decapitated. Wary of his brother's vast power even in death, Horazon ordered that Bartuc's body be forever hidden from the sight of Man. In this he and the Vizjerei were aided by the Priests of Rathma.
The Arcane Sanctuary
Though a powerful Summoner, Horazon feared that the Lords of Hell would punish him for enslaving their brethren. His mind shattered by the horrific experiences he had gone through, he travelled to Aranoch, where he tried to engage in a life of studious pursuit. He built the Arcane Sanctuary, and kept demons as slaves within the structure. He retired to the Sanctuary disappearing from the public eye, which he believed would keep him free of Hell's reach, but would also allow him to continue his studies free of the ravages of time and disease. Horazon crafted many wondrous scrying devices through which he observed the events of the world outside. This included the imprisonment of Baal within Tal Rasha's Tomb. He wrote down his observations in his journal and provided clues for adventurers seeking the True Tomb amongst the six False Tombs.
Earth and Stone
Horazon continued to reside in his Sanctuary, remaking it over and over, even as his body began to give out on him. Then came the day where Horazon gave what was left of himself to the Sanctuary. In essence, Horazon became the Arcane Sanctuary itself.
At some point, a curious Sorcerer found his way into the Sanctuary by accident, losing his senses in the process. Feeling guilty, Horazon did what he could for him, though the Sorcerer effectively became a vessel of Horazon himself. This appeared to fragment Horazon's consciousness, dividing it between the shell and the Sanctuary.
Legacy of Blood
Even in death, the bond between Horazon and Bartuc remained. Norrec Vizharan, who had come to wear the armour of Bartuc, found his way to Lut Gholein, where the Arcane Sanctuary was buried under, such as the bond between the brothers. Horazon sensed the presence of the Necromancer Kara Nightshadow in the city above and sent his shell to find her.
As part of her efforts to find Norrec, Kara found her way into the Sanctuary. A number of mosaics came to life and attacked her, but she was saved by Horazon himself (or rather, the shell of the Sorcerer he had commandeered). He appeared to barely have left of his senses, but upon the mention of Bartuc, he led Kara deep into the Sanctuary, seeking refuge from his brother. Horazon brought her to a bedroom and told her to sleep, locking her in. He retired to drink wine and eat food. Seeing Kara (having made her way through the Sanctuary), he bid her sit with him (the fact that he was seated upside down due to the Sanctuary's insane geometry aside) and eat, a feat which she accomplished. As they sat, Horazon spoke of his past when Kara tried to get information out of him. However, his words were like babble, and incoherent. At one point he spoke of having discovered the Sanctuary by accident. At another, he told her of how he had come to Aranoch to study the ley lines around what would become Lut Gholein. But after that, he said that he had fled to Aranoch in a bid to escape his brother's dark legacy. As the conversation progressed, Kara got the sense that she was talking to two different people. One who actually was Horazon, and one who thought he was Horazon (a side effect of Horazon's fragmented mind). She supposed that his experiences in the Mage Clan Wars, coupled with centuries of isolation, had torn apart his mind. In truth, Horazon was actually learning about her, just as he had done when she had slept.
With the meal finished, Horazon led Kara through the Sanctuary but began to quiver in fear as he sensed the presence of Norrec (and through him, Bartuc's armour). He told Kara that she had to go, while he had to hide. However, the Sanctuary appeared to take on a mind of its own, hands literally jutting out to grab him, and force him to confront his foe. He did battle with Norrec, but Kara realized that the armour was controlling Norrec. Kara begged Horazon to stop, but he kept fighting. Norrec asks whether "Horazon [is] just like his brother?" From every wall, every ceiling, mouths took form and answered for their maker...
Blood Calls to Blood
The Arcane Sanctuary took it upon itself to expel Kara and Norrec, but Horazon made no appearance. At least not until after the siege of Lut Gholein by Augustus Malevolyn, where Horazon appeared before Norrec. Kara, at last, realized Horazon's true nature, and he explained it as such to her. Through Norrec, Horazon conversed with his brother, whose dark legacy still persisted through the armour he wore. Through magic, Bartuc's armour was ripped off Norrec, and was worn by Horazon himself, but unlike Norrec, he did not lose himself. He told Kara to never again seek the Arcane Sanctuary and told Norrec to create his own legacy. With all said and done, his body began to crumble, joining the sands of Aranoch, taking Bartuc's armour with him. Ending the legacy of the two brothers.
The False Summoner
During the time of Diablo's resurgence, it was doubted Horazon still lived. In their pursuit of the Dark Wanderer, adventurers fought their way through hordes of demons running rampant in the Arcane Sanctuary. There they discovered a dark impersonator: one of the Vizjerei sorcerers that attempted to save Tristram who had been corrupted and styled himself The Summoner. He was slain by the adventurers. Deckard Cain suggested that the impersonator was pulled down to Hell by the forces of Evil after his death. Others suggest that it was Horazon's spirit that possessed the sorcerer.
Personality and Traits
Horazon was ambitious, and delighted in breaking the will of demons, though turned away from this path at the end of the Mage Clan Wars. Deckard Cain was of the opinion that Horazon was perhaps one of the greatest mages who has ever lived, but noted that for all his power over demons, that might not have been enough to save Horazon from death and/or the reach of Hell. However, at the least, Horazon managed to live well over 1000 years, as he was able to be present for both the Mage Clan Wars and the final days of the Dark Exile.
The legend of Horazon is well known to the people of Lut Gholein, and over time, many feats and strange events were attributed to him. Such legends were not entirely positive, however, and in some, Horazon was portrayed as being the lesser of two evils when compared to Bartuc, for, after all, he had engaged in the summoning of demons himself. The legends claimed that Horazon's actions in the war were down to self-preservation. The Vizjerei still revere Horazon as a symbol of humanity's ability to triumph over otherworldly forces. The Zakarum, however, cite him as an example of mankind's folly.
At the end of his life, Horazon's grip on sanity was loose, and his body was failing him. Thanks to the body he had taken, he looked like a beggar, with long white hair, including a beard, along with blue eyes. His mind was ravaged by his experiences in the Wars, his fear of Bartuc, and centuries of isolation within the Arcane Sanctuary. Nonetheless, Norrec noted that while Horazon looked like a beggar, he radiated a sense of presence that made those around him seem insignificant. Also, in these last moments, Horazon appeared in full control of himself. It was now clear to those present that Horazon had no further desire to be part of the world.