Khala

The Khala, the "Path of Ascension," was the principal religion of the Khalai protoss and the communal psionic link that bound all its adherents together. Founded on a psionic philosophy that maintained a shared bond of emotion among its followers, it divided them into at least five levels of adepts and could not be permanently broken once joined, except by severing the nerve cords, though drugs and certain psionic abilities could sever an adherent from it temporarily. The Nerazim and the Tal'darim never used the Khala: the former viewed it as the robbing of individuality, and the latter never submitted to it. (StarCraft; StarCraft: The Dark Templar Saga: Shadow Hunters; StarCraft: Frontline Volume 1; StarCraft II: Legacy of the Void)

The original link and its breaking#

In their plot to create the perfect creatures to end the Infinite Cycle, Amon and the xel'naga who followed him broke their rule of noninterference and came to Aiur. Seeing in the protoss the potential for purity of form, they manipulated the natural psionic link the species had developed in order to accelerate it. After a millennium of subtle work the xel'naga revealed themselves and interacted with the nascent species directly, but they soon found that the maturing tribal structure and the rise of individualism were eroding the psionic link. Eventually the link broke: the protoss could still communicate telepathically and read one another's thoughts, but the empathic bond was lost. Regarding the experiment as a failure, Amon's xel'naga departed Aiur, and the protoss fell into the Aeon of Strife. (StarCraft II: Legacy of the Void; StarCraft: The Dark Templar Saga: Twilight)

Khas and the founding of the Khala#

Near the end of the Strife, a protoss named Savassan, later known as Khas, "he who brings order," found the khaydarin crystals the xel'naga had left behind on Aiur. Touching the crystals, he rediscovered the psionic link, and with knowledge drawn from other xel'naga relics he learned how to rekindle the empathic bond. He recorded these findings as the founding precepts of the Khala so that the protoss might once more become a unified communal society. Many protoss both revered and hated the xel'naga, and that hatred had fueled the Strife; Khas held that the protoss did not need their makers, only the once-lost emotional link, and that embracing the positive emotions all protoss shared could negate their destructive self-hatred. In this way Khas ended the Aeon of Strife and brought on the protoss Second Age. Unknown to Amon or the protoss, the creation of the Khala disturbed the loyal xel'naga from their slumber and led them to discover Amon's plot. (StarCraft; StarCraft: The Dark Templar Saga: Firstborn; StarCraft: The Dark Templar Saga: Shadow Hunters; StarCraft II: Legacy of the Void)

The shape of protoss society#

Built on the Khala, protoss society restructured itself into three castes: the Judicator Caste led by the Conclave, the Khalai Caste, and the Templar. When the protoss became an active interstellar civilization once more, the Khala led them to adopt the Dae'Uhl, the "Great Stewardship," over the less advanced species they encountered. Those who followed the Khala were often called Khalai in a broader sense than membership in the caste, and moments of great weight in protoss society could be felt through the whole of it, with all protoss sounding together as one in response. Being subsumed in the Khala meant a certain loss of self alongside the gain of the "other," and the loss could be drastic; some protoss rejected it and severed their long head nerve cords to cut the empathic link. These outcasts formed the Rogue Tribes and, after their banishment from Aiur, became known as the Nerazim. (StarCraft; StarCraft: The Dark Templar Saga: Shadow Hunters)

How the Khala was used#

It was very hard for Khalai to hide from one another through the empathic link, though non-adherents such as the Nerazim could still conceal themselves. The depth of the connection varied by personal choice, and full immersion in unity at all times was difficult to maintain. Members of the Templar and Judicator Castes, along with many Khalai, immersed themselves deeply several times a day, nourishing themselves through the rich contact and emerging refreshed; the nectar of the plant alavash was often used to strengthen the connection. Because the link carried emotion as well as thought, Khalai found it difficult, though not impossible, to hate one another, and in times of great loss all connected protoss felt the weight of the tragedy and sounded together in shared grief. (StarCraft: The Dark Templar Saga: Shadow Hunters; It Will End in Fire; StarCraft Field Manual)

The discipline of the Khala was required to control abilities such as the psionic storm, and the Khala granted a protoss an enormous reserve of psionic energy, with strength measured in levels, fifth-level adepts being considered extremely powerful. The fortitude of the Khala also protected the protoss from assimilation by the zerg. Through the Khala, the Khalai dead "entered" the link but did not remain as coherent entities; rather, resonances of their last thoughts and experiences lingered, which living protoss could sense, sometimes with the aid of the Templar Archives, though only preservers had full access to this knowledge. According to tradition, after death the Khala was an unending chorus of minds woven in harmony and joy, growing stronger as more spirits entered it. (StarCraft; StarCraft: Frontline Volume 1; StarCraft: The Dark Templar Saga: Twilight; Cold Symmetry)

The corruption and end of the Khala#

During the reclamation of Aiur in the End War, Amon returned to the material universe. Lacking a host body, he asserted his consciousness into the Khala itself, which let him sustain himself in the material world while controlling every protoss bound to it. The Dark Prelate Zeratul cut the nerve cord of Hierarch Artanis at the cost of his own life, freeing Artanis, who rallied what unconnected protoss he could and escaped Aiur. Those who had mastered every intricacy of the Khala could resist Amon's possession, but only for a time, and from there Amon used the corrupted protoss of the Golden Armada to purify worlds in his crusade against all life. (StarCraft II: Legacy of the Void)

Phase-smith Karax, working with the Keystone, discovered a way to pull Amon out of the Khala temporarily; if the protoss around him severed their nerve cords while he was extracted, he would have no host to occupy and would be cast back into the Void. Allying with the Nerazim, who had already severed their connection, the Tal'darim, who had never formed one, and the Purifiers, Artanis destroyed Amon's host body on Aiur and used the Keystone to draw Amon from the Khala. The remaining protoss under Amon's control then severed their nerve cords, cutting the psychic link shared among all Khalai and ending the Khala. Artanis set out to build a new protoss society bound not by the Khala but by the unity of their race. Even five years on, the protoss still struggled with the wound the loss had left, many Khalai finding themselves without contact or purpose, and radical attempts to forge a new Khala using Nerazim and Purifier technologies often killed those who tried. (StarCraft II: Legacy of the Void; StarCraft: Evolution; One People, One Purpose)