Though this proved effective at first - Uldyssian and his nephalem banished Lucion and toppled the Triune - Lilith eventually lost control of the situation. Uldyssian's followers also had access to their nephalem potential, allowed for by Uldyssian's alteration of the Worldstone's attunement, allowing the Edyrem's powers to grow. Uldyssian led a band of followers called the Edyrem against the two bodies, for they saw them as the source of Kehjan's strife. To this end, she weakened the dampening effect of the Worldstone and manipulated a simple farmer - Uldyssian - into removing the main obstacles: the Triune and the Cathedral. However, at the war's end, 3000 years before the darkening of Tristram, the precarious balance between the Triune and the Cathedral dissolved due to the return of Lilith, who once again sought to bring the power of the nephalem under her control. The status quo between the two bodies was maintained, as agents of both religions carried their messages to the people, building bases of power, constructing monuments, and winning the absolute loyalty of faithful supplicants. The rise of these two religions polarized Kehjan society as their ideological battle continued over the next decade.

And so the great game had begun: a secret war of subterfuge and manipulations, with humanity as its grand prize. However Inarius noticed the intrusion, and created a counter-sect - the Cathedral of Light - that preached the teachings of the Light. This cult would win over humanity to its side, gradually turning them over the side of Evil. The Prime Evil Mephisto sent his son, Lucion, to the realm, where he established a cult - the Triune. In order not to alert the High Heavens, the forces of Hell opted for the subtle approach. Control over Sanctuary and its mortal population could gain the decisive advantage in the Great Conflict. The demons took notice of the mortal inhabitants of Sanctuary and realized its strategic value. What they didn't know was that their actions had alerted Hell to the existence of Sanctuary. The Vizjerei Clan had long sought to summon 'spirits,' but having discovered the existence of demons, they began to summon them frequently and in ever increasing numbers, hoping to learn more about the universe and magic. It was the Burning Hells which first discovered the realm, because of the reckless actions of Jere Harash.

Not fully able to eradicate the nephalem, Inarius now sought to contain their abilities, manipulating the Worldstone to dampen their powers.ДЇor a while all seemed right, but eventually both sides of the Conflict were bound to take notice of Sanctuary. For her transgressions, Inarius banished her to the Void. To this end she murdered most (if not all) of the renegade angels and demons. She realized the nephalem had the potential to become more than both angel and demon, and wanted to harness their power for her own ends. Inarius wanted to eradicate the nephalem or 'first born', whom he eyed as abominations, but it was Lilith who first saw their potential. Inarius made certain his former masters - and enemies - would not find his refuge as he shielded the realm from outside interference.ДЇrom the union of angel and demon the nephalem were created. Inarius also fell in love with a like-minded demoness, Lilith. After stealing the primal Eye of Anu, the ancient Worldstone, Inarius created a realm he called Sanctuary, where the renegade angels and demons could live in peace. With the other members of the Council, even Tyrael, refusing to see Inarius's 'reason', he gathered like-minded individuals from both Heaven and Hell, and led them far away from the carnage. It was Inarius, tactical advisor to the Angiris Council of the High Heavens, who would eventually grow tired of the constant planning, counterplanning, and even counter-counterplanning. Attacks on one side would be repaid by counterstrikes legions of demons and angels were obliterated in the process, but without causing a significant breakthrough. The war between the High Heavens and Burning Hells was an everlasting conflict and as such, a stalemate.

The Holy Scriptures of Zakarum (excerpt) ( src) 'No more will these creatures deny us,' swore the Prime Evils, 'for we are greater than they.' And thus began the Sin War.' 'And the hosts of Hell looked upon man, and swore vengeance for their defeat by the Vizjerei.

Diablo the sin war