Over time, demonic entities made their way into the Titansâ€™ worlds from the Twisting Nether, and the Pantheon elected its greatest warrior, Sargeras, to act as its first line of defense. A noble giant of molten bronze, Sargeras carried out his duties for countless millennia, seeking out and destroying these demons wherever he could find them. Over the eons, Sargeras encountered two powerful demonic races, both of which were bent on gaining power and dominance over the physical universe. The eredar, an insidious race of devilish sorcerers, used their warlock magics to invade and enslave a number of worlds. The indigenous races of those worlds were mutated by the eredarâ€™s malevolent powers and turned into demons themselves. Though Sargerasâ€™ nearly limitless powers were more than enough to defeat the vile eredar, he was greatly troubled by the creaturesâ€™ corruption and all-consuming evil.
Incapable of fathoming such depravity, the great Titan began to slip into a brooding depression. Despite his growing unease, Sargeras rid the universe of the warlocks by trapping them within a corner of the Twisting Nether. While his confusion and misery deepened, Sargeras was forced to contend with another group intent on disrupting the Titansâ€™ order: the Nathrezim. This dark race of vampiric demons (also known as dreadlords) conquered a number of populated worlds by possessing their inhabitants and turning them to the shadow. The nefarious, scheming dreadlords turned whole nations against one another by manipulating them into unthinking hatred and mistrust. Sargeras defeated the Nathrezim easily, but their corruption affected him deeply.
As doubt and despair overwhelmed Sargerasâ€™ senses, he lost all faith not only in his mission, but also in the Titansâ€™ vision of an ordered universe. Eventually he came to believe that the concept of order itself was folly, and that chaos and depravity were the only absolutes within the dark, lonely universe. His fellow Titans tried to persuade him of his error and calm his raging emotions, but he disregarded their more optimistic beliefs as self-serving delusions. Storming from their ranks forever, Sargeras set out to find his own place in the universe. Although the Pantheon was sorrowful at his departure, the Titans could never have predicted just how far their lost brother would go.