Kain in Blood Omen
Kain was a nobleman, from the city of Coorhagen. He grew up completely unaware of his greater destiny: that he had been selected from birth to become the Guardian of the Pillar of Balance.
In Blood Omen, Kain was thirty years old. For reasons unknown to him, he was assassinated by brigands outside a tavern in Ziegsturhl. Strangely he was saved from oblivion by Mortanius the Necromancer, and offered a chance for vengeance against the instigators of his murder. In the Underworld, bound to wooden posts and still impaled by his assassin's sword, Kain accepted. He didn't consider the cost or the Necromancer's motivations. "Nothing is free. Not even revenge..." He was resurrected as a vampire.
Kain quickly killed the brigands who had carried out the deed, then continued to the Pillars, hoping to find clues about the identity of their employer. There he encountered Ariel for the first time. She told him that there was "no cure for death, only release", and that he would only know peace after he had restored the Pillars of Nosgoth. Only then would his curse end. Kain heeded Ariel's guidance, and began his quest to kill all of the corrupted Guardians. Nupraptor the Mentalist was his first target.
Kain travelled north, passing through several townships. He reached Nupraptor's Retreat and beheaded the Mentalist. However, Kain soon realized his task was far from a simple one. A major obstacle existed in the form of Malek, the Guardian of the Pillar of Conflict. As the protector of the Circle, he was not about to let Kain assassinate them one by one. After a confrontation at Malek's Bastion, where Kain was forced to flee, Ariel suggested that the Oracle of Nosgoth might aid him.
Kain approached the Oracle, and questioned him about how to defeat Malek. The Oracle - none other than Moebius the Time Streamer - directed Kain towards the powerful and ancient vampire, Vorador. He also gave enigmatic pointers toward the kingdom of Willendorf. Kain was unaware that Moebius had an ulterior motive hidden in his helpful advice, and followed the Oracle's path. He met with Vorador.
The elder vampire warned Kain to stay out of human affairs, but offered his assistance if Kain ever needed him. Vorador had defeated Malek five centuries before, and keeping Vorador's signet ring, Kain was able to summon him when he faced Bane, DeJoule and Malek at Dark Eden. Malek was finally laid to rest there, and the other two Guardians fell to Kain's sword.
Kain visited Avernus Cathedral, and claimed the Soul Reaver sword as his own. He killed Azimuth, then continued to Willendorf. By hunting Elzevir and returning the soul of King Ottmar's daughter, Kain was able to rouse the army of Willendorf against the Legions of the Nemesis. However, Ottmar's army was defeated in the Battle of the Last Stand. After the king died, Kain escaped from the battlefield using a Time Streaming Device he had discovered opportunely, earlier in his travels. The device transported Kain fifty years into Nosgoth's past, a time when William the Just - the king who would become the Nemesis - was still a boy. Kain took it upon himself to fight and kill William for the greater good of Nosgoth, blissfully ignorant of the magnitude of his mistake.
Moebius had orchestrated Kain's trip through time in order to ignite a genocidal war against the vampires. William's loyal subjects, devastated at the loss of their beloved king, were willing to follow Moebius instead. They became his mercenary army, resolute to rid Nosgoth of the 'unholy scourge'. Kain returned to the present just in time to watch the public execution of the last vampire in Nosgoth, save himself - Vorador. Finally seeing how he had been manipulated, Kain battled Moebius into submission, and cleaved his head from his body.
Returning to the Pillars once more, Kain witnessed a conversation between Mortanius and Anarcrothe. Mortanius admitted his part in Kain's resurrection and assassination, but justified it as being for the good of Nosgoth; the Circle's corruption meant it had to be destroyed. Anarcrothe objected to the Necromancer's willingness to sacrifice all their lives. They fought, and as the Alchemist died, seven of the Circle were no more. Kain approached Mortanius, and was welcomed, although Mortanius warned that he was not the last surviving Guardian. There was still one more, whom Kain had not yet met.
Kain defeated Mortanius, and the Dark Entity that had possessed him emerged from his body. The Dark Entity taunted Kain for allowing himself to be used by others, and they battled. Kain emerged victorious, but he was left with a terrible dilemma. Suddenly the truth became clear to him, and Kain knew he was the last Guardian.
The fate of Nosgoth rested on Kain's decision. He could sacrifice himself to restore the Pillar of Balance, or he could plausibly take control of Nosgoth. He was now likely the most powerful creature in the land. Kain also was the last remaining vampire. Feeling no compassion for the humans that had hunted his kind to extinction, he chose to reject the idea of self-sacrifice. Roughly a millennium and a half later, Kain's empire stretched across Nosgoth.
Kain in Soul Reaver
In Soul Reaver, Kain ruled a world dominated by vampires. He had raised six elite Sarafan warriors from their tomb to serve him, leaving their past forgotten. The human kingdoms were conquered, and these vampire lieutenants created many offspring. Their control of Nosgoth became all but complete as the Pillars continued to decay. The few rogue elements - humans trying to rid Nosgoth of 'the vampire scourge' and lesser vampires - were tolerated for amusement's sake, and to challenge the young.
As the Emperor/King of Nosgoth, Kain's throne was at the base of the eternally corrupted Pillar of Balance. His appearance had changed from his Blood Omen incarnation; centuries of vampiric evolution had transformed his body into a muscular 'higher form'. In his left ear, he wore Vorador's signet ring as an earring. He still bore the scar - misshappen and somewhat displaced by his altered physique - of the wound that ended his mortal life. Kain was "deified" (considered to be a god), and few in Nosgoth realized he had once been human.
One day, Raziel - the first-born of Kain's lieutenants - arrived at the Pillars. He had grown wings, surpassing Kain's own evolution. Kain reacted badly, and ordered Raziel's execution, apparently because of jealousy. Raziel returned from the Abyss - as a soul-devouring wraith - wanting to destroy Kain for discarding him so lightly despite all his loyalty. They fought twice; the second time was at the Chronoplast. Kain led Raziel into Nosgoth's past.
Kain in Soul Reaver 2
In Soul Reaver 2, Raziel sought Kain with Moebius' guidance. He found Kain at the Pillars and saw the corruption of the Pillars happen while they were there. Kain explained that as Ariel died, he had been born, and thus being part of the Circle even at that early time, he was exposed to the madness of Nupraptor, her grieving lover. Raziel's anger towards Kain started to abate, as his own destiny and past were beginning to catch up with him.
During their encounters in different eras, Kain revealed more of his agenda. He wanted Raziel's assistance to reclaim the destiny he had been denied. In return, he would help Raziel achieve his true destiny. Kain was searching for a third option for the decision he was forced to make as the last tainted Guardian, one that could really restore Nosgoth. The choice he was given at the end of Blood Omen was rigged, and neither his self-sacrifice or survival would have solved anything properly. He had seen the future in Moebius' Chronoplast, and stumbled upon the possibility of finding the elusive third option. But it was a risky path to take. It would involve the manipulation of history, and Raziel was the crucial player. His 'execution' had been necessary.
Kain was able to persuade Raziel to spare his life when history dictated that he should have died. Then there was a second defiance of history that Kain believed would deliver Nosgoth's salvation.
Raziel was being drawn into the Reaver blade when Kain interfered, wrenching the sword from Raziel's body. This altered the course of history again, as he expected, but something had gone wrong. As new memories - reflecting the alteration - were created in Kain's mind alongside his old recollections, he knew that Janos Audron - recently murdered by the Sarafan - must remain dead. He also knew that his actions had ultimately aided the ancient race: the Hylden, the eternal adversaries of the vampires. The events of Blood Omen 2 - part of Nosgoth's new timeline - had taught Kain just how dangerous they were.[2,3]