Xel'Naga

The xel'naga were a highly advanced race of god-like entities originating from the Void, described as the most powerful species the universe has ever known. They were known by many names, "wanderers from afar," and to the protoss the Ihan-rii, the Great Teachers, the Makers, and the Guardians, who once worshipped them as gods. By protoss tradition they were peaceful and benevolent, utterly consumed with studying and propagating the evolution of sentient life, and they shaped the destinies of both the protoss and the zerg toward an ancient purpose called the Infinite Cycle.

The Infinite Cycle#

Originating from the Void, the xel'naga were incredibly long-lived even by protoss standards, but not immortal, and in the interest of their species' survival they sought to create new xel'naga by uplifting two species. Two qualities were required, defined as purity of essence and purity of form, and each uplifted species was guided toward one of them; over an extraordinary span of time the two would naturally come together and merge, forming the next generation of xel'naga and beginning the cycle anew. This Infinite Cycle had repeated across numerous universes, the xel'naga taking physical form at each universe's creation to seed it with life, so many times that time itself was affected by it.

Some among the xel'naga, however, resented being uplifted into their god-like forms and saw the cycle as horrid, dependent on the conflict of others for the benefit of the xel'naga. Under a powerful xel'naga named Amon, this rogue faction sought to undo the xel'naga's work, purge the universe of their creation, and remake a perfect universe without the strife of the cycle. The loyal xel'naga, meanwhile, slumbered within the Chamber of Ascension at Ulnar, waiting for the two destined races to assemble the Keystone and find their way to them.

The making of the Firstborn#

Seeing their opportunity, Amon and his followers left Ulnar and turned to the jungle world of Aiur, one of the xel'naga's engineered worlds, where they found their most advanced creation yet. They named the new race the protoss, "the Firstborn," accelerated their evolution, and spent a millennium subtly guiding their steps, using devices such as the Kassia crystal to enhance their rate of reproduction. When the protoss reached full sentience, Amon's xel'naga revealed themselves and integrated into protoss culture, marveling at how driven their creation was to plumb the mysteries of the universe.

In time the protoss tribes grew apart, and as individual egos rose to overpower the communal psychic link, many of Amon's followers concluded that the protoss had lost their greatest strength. Deeming the purity of form they sought to be sullied by a conflict of essence, they declared the protoss a failed creation and prepared to depart. Hundreds of Amon's xel'naga were killed in a protoss attack as they tried to leave, but enough worldships were launched, and they left behind khaydarin crystals and at least one ship. Their departure plunged the protoss into the Aeon of Strife.

The broken cycle#

Amon and his followers traveled to Zerus, where they abandoned their concern for physical form and pursued purity of essence alone, advancing the evolution of the zerg until the once-insignificant species could survive the planet's firestorms and, eventually, the harshness of space. To avoid repeating the protoss failure, they structured the collective sentience of the Swarm into a single hive mind, creating the Overmind to control it and watching over it through a psychic link. When the protoss created the Khala, the resulting absence within the Void itself disturbed the loyal xel'naga from their slumber. Discovering Amon and his followers at Zerus, they made war, and Amon unleashed the zerg in response. The xel'naga defenses were overrun within hours, and the greater whole of the race was consumed, throwing their plan into turmoil. Amon was felled in the final confrontation and thrust back into the Void, where he twisted it with his hatred, while a fraction of the xel'naga survived within Ulnar and one of Amon's servants set out to find a body to sustain him.

Return and the end of the cycle#

Millennia later, fragments of an ancient prophecy foretelling the return of the xel'naga drew both Zeratul and Sarah Kerrigan into a search for the truth, while Crown Prince Valerian Mengsk and his Moebius Foundation scoured the Koprulu sector for xel'naga artifacts and the pieces of the Keystone. After the Keystone was used on Char to restore Kerrigan, the energy was turned by the Amon-aligned scientist Narud to release Amon from the Void. The surviving xel'naga wished Kerrigan restored as leader of the Swarm and guided her, through Zeratul, to Zerus, where she was reborn as the Primal Queen of Blades, free of Amon's influence.

When Amon returned in full during the End War, he corrupted the Khala and possessed the protoss bound to it. The Daelaam and the Zerg Swarm reached Ulnar to find the xel'naga in the Chamber of Ascension already slain, and the war moved into the Void itself. There the last of the xel'naga, Ouros, who had spoken through the memory of Tassadar, urged Kerrigan to merge with his essence so that she might ascend and continue the cycle against Amon. Kerrigan agreed; with Ouros giving his life, the Infinite Cycle came to its end and Kerrigan ascended as a xel'naga. Defended by Jim Raynor, Artanis, and Broodmother Zagara, she then destroyed Amon's void crystals and defeated him.

Biology, culture, and technology#

Xel'naga biology varied with the individual. Many, including Ouros, Amon, and the figures depicted in the xel'naga temples, took the form of a large squid-like creature with a bulbous body, while others such as Narud were great hunched beings, and Sarah Kerrigan's ascended form was that of a winged figure wreathed in flame. The xel'naga and creatures carrying their essence could passively quicken the growth of life around them, raising flora and fauna even on dead worlds, and their genetics held a depth of molecular and quantum complexity the races of the Koprulu sector could not grasp. Culturally they cherished all life and refused to kill anything, a philosophy the protoss later echoed as the Dae'Uhl, and they used a universal proportion the protoss called ara'dor, the "perfect ratio," which terrans knew as the Golden Mean.

Their technology rested on the understanding that energy, essence, and information were one and mutable, freely converted from one state to another. They made liberal use of khaydarin crystals, left numerous artifacts and temples scattered across worlds such as Aiur, Aridas, Ehlna, and Bhekar Ro, and built constructs and space platforms guided by their own forms of artificial intelligence. Much of their work was, to the protoss, akin to magic: some artifacts could manipulate the minds of terrans, some were immune to conventional weaponry, and some shielding could even turn aside the psionic powers of the Khalai. After Amon's defeat the Daelaam gathered xel'naga corpses for study, and Kerrigan's parting gift to the Swarm included the means for the zerg to create the adostra, a breed that could regenerate life on dead worlds as the xel'naga once had.