Mind control: psionic domination in the Koprulu Sector

Mind control was a type of psionic power known throughout the Koprulu Sector, the ability of one mind to seize the actions, and sometimes the memories, of another. It appeared in nearly every corner of the sector's history and in nearly every species. Among the protoss it belonged to the judicators and the dark archons. Among terrans it was a rare gift hunted for by the Terran Dominion and its ghost program. Sarah Kerrigan used it to enslave a Matriarch, the hybrid used it to turn protoss guardians against their own charges, and Amon used it, through the corrupted Khala, to puppet almost the whole of a civilization. (StarCraft: Brood War; StarCraft II: Wings of Liberty; StarCraft II: Nova Covert Ops; StarCraft II: Legacy of the Void)

Protoss mastery#

The protoss counted mind control among their psionic arts, though its two chief forms could hardly have been less alike. The judicators, the governing caste of old Aiur, used their powers with subtlety, quietly influencing the minds of other creatures rather than seizing them. The dark archons of the Nerazim practiced something far more direct and far more costly. Through an immense expenditure of energy, a dark archon could project a portion of its own psychic essence into another being, gaining control over the victim's actions and access to its memories. The technique made no distinction of species; terran soldiers and zerg organisms alike could be torn from their former masters and bound to the archon's will. (StarCraft: Brood War)

The enslavement of Raszagal#

The most consequential act of mind control in protoss memory was committed not by a protoss but against one. Sarah Kerrigan possessed mind control powers of her own, and she used them to enslave Raszagal, Matriarch of the Nerazim, during the Brood War. The corruption went unrecognized on Shakuras for some time. While Artanis, Kerrigan, and Zeratul were away retrieving the Uraj and Khalis crystals, it was Aldaris who discovered that Kerrigan had somehow corrupted the Matriarch's mind. The judicator answered the revelation the only way he could, rallying a legion of Templar in open revolt against the Nerazim and the influence hiding behind their leader. His warning came too late to break the Queen of Blades's hold on Raszagal, and the Matriarch remained her instrument. (StarCraft: Brood War)

Whispers, suggestion, and possession#

Not all mind control announced itself. Sufficiently powerful psionics could work in a gentler register, reaching out across long distances to implant ideas and suggestions in a target's mind without the victim ever knowing another will had touched his own. Such suggestion had limits; those with stronger wills were able to resist it. At the farthest extreme of the art stood the entity known as the Voice in the Darkness, which did not merely nudge its victims but controlled terrans and protoss outright, effectively possessing them. Between the whisper and the possession lay the whole spectrum of psionic domination, and the sector's histories recorded examples at every point along it. (StarCraft II: Nature of the Beast; StarCraft: Frontline Volume 4)

Ghosts of the Terran Dominion#

Among terrans, mind control was a rare talent and a coveted one. It was considered one of the most highly sought after abilities among Terran Dominion ghost recruits, and the Dominion built hardware to make the most of those who possessed it. The indoctrination visor was designed to sharpen such talents, and Nova Terra, one of the Dominion's most capable operatives, wielded mind control herself. The co-op missions add further instruments to sharpen the gift. The psionic motivator let a ghost increase the combat ability of those under her control, the neural disruption device caused enemies around a dominated target to turn their guns on one another, and the type-88 persuader lengthened the time a ghost could hold a captured mind. Terrans feared the power as much as they prized it. After Edmund Duke defected to the Sons of Korhal, a faked news report accused Arcturus Mengsk of releasing mind-control drugs on Antiga Prime. (StarCraft II: Nova Covert Ops; StarCraft II: Wings of Liberty; StarCraft II Co-op Missions; StarCraft: Liberty's Crusade)

The spores of Vygoire#

Mind control was not always the work of a mind at all. On the planet Vygoire grew a special breed of spore capable of mind controlling and telepathically linking those infected by it. An ultralisk known to terrans as the Great One assimilated a number of these spores, and as the infection spread, the spore-infected researchers nearby came to worship the beast. The phenomenon drew official attention after a science outpost on the supposedly zerg free world fell silent; the marine platoon Torch Seven dropped onto Vygoire to learn what had become of a research base that had failed to report in for nearly six months, and found the spore's congregation waiting. (Great One)

The hive mind emulator#

The zerg Swarm, itself an empire built on the domination of lesser minds by greater ones, eventually found its own control turned against it. During the Second Great War, Egon Stetmann, a scientist working for Raynor's Raiders, isolated the DNA strand that had been used to create the zerg Overmind. He applied that strand to the design of the hive mind emulator, a terran structure that could mind control most zerg strains, stealing creatures bred for the Swarm and setting them to fight in its enemies' lines. (StarCraft II: Wings of Liberty)

Hybrid dominators#

The protoss zerg hybrid inherited domination as a birthright. The hybrid destroyer Maar could mind control protoss, and on the archive world Zhakul he subverted the Zhakul Guardians, the very warriors sworn to protect the three preservers he had imprisoned and was slowly draining of their essence. When Zeratul came to Zhakul aboard the Void Seeker seeking the preservers' wisdom, he found the guardians raised against him and their captor feeding on the powers of the minds it had caged. Jim Raynor, who later experienced the encounter secondhand through an ihan crystal, recognized in Maar a fusion of protoss and zerg and understood the scale of the threat. Nor was Maar unique among his kind; hybrid reavers could exert mental control over both zerg and terrans. (StarCraft II: Wings of Liberty; StarCraft II: Legacy of the Void; Sector Six)

Amon and the corruption of the Khala#

Every earlier act of mind control was a rehearsal beside what came in the End War. Amon and his hybrid demonstrated the ability to mind control terrans and zerg alike, but his masterstroke was aimed at the protoss. Through the Khala, the communal psionic link binding the Khalai, Amon took numerous protoss under his thrall the moment he corrupted it during the reclamation of Aiur, among them Hierarch Artanis himself. Zeratul fought the possessed Hierarch and, in a final effort, severed Artanis's nerve cords to cut his link to the Khala, freeing him at the cost of Zeratul's own life. The war for the protoss mind ended only when the Keystone extracted Amon from the Khala and Artanis convinced Selendis and the freed Templar to sever their nerve cords as well, cutting themselves off from his influence forever and casting the dark god back into the Void. Its defeat required a species to give up the very link that had defined it. (StarCraft II: Legacy of the Void)