Mind control

"Worms. It felt as if worms were burrowing through his brain...It was worse than any head pain he had experienced before."

- Dorian, suffering the early stages of mind control from a hybrid reaver

Mind control is a type of psionic power.

Overview
Protoss are able to use mind control. Judicators could use their powers to subtly influence the minds of other creatures. Dark archons however, through an immense expenditure of energy, are able to project a portion of their psychic essence into another being, gaining control over its actions and access to its memories.

The infested Sarah Kerrigan had mind control powers as well, and used these abilities to enslave Matriarch Raszagal.

Mind control is considered to be one of the most highly sought after abilities among Terran Dominion ghost recruits. The indoctrination visor was designed to amplify these talents among terrans who posess the ability. Nova Terra is capable of mind control.

The Voice in the Darkness is also able to control terrans and protoss, effectively 'possessing' them.

The hybrid destroyer Maar could mind control protoss as well, subverting the Zhakul Guardians. Hybrid reavers can exert mental control over both zerg and terrans.

During the Second Great War, Egon Stetmann, a scientist working for Raynor's Raiders, isolated the DNA strand used to create the zerg Overmind. He applied this to design the hive mind emulator, a device that could mind control most zerg strains.

During the End War, Amon and his hybrid demonstrated the ability to mind control terran and zerg, and through the Khala, mind control Khalai protoss.

StarCraft
If mind control is used on units from other races, the dark archon's controller will have access to the supply of that race. Terran and zerg units and buildings become available by mind controlling SCVs and drones; thus, protoss armies have the potential to expand their military powers dramatically should they have the resources to do so. For example, a protoss player with a large surplus of minerals and gas mind controls an SCV. While he/she had a potential of 200 protoss supply before, he/she now has a potential of 200 protoss and 200 terran supply. Such occurrences, however, are rare in higher-level competitive gaming due to the efficiency and speed at which players use up their resources.

Wings of Liberty
The hive mind emulator can mind control all zerg units except heroic units and drones.

Legacy of the Void
Mind control is available as an ability for the dark archon in the Legacy of the Void campaign. Ultralisks cannot be mind controlled.

Nova Covert Ops
Mind control is available as an ability for Nova in Nova Covert Ops after acquiring the indoctrination visor in the level "In the Enemy's Shadow."

Co-op Missions
Mind control is available as a researched ability for Vorazun's dark archons once she reaches level 9. It can be researched from the dark shrine. Heroic units are immune and mind controlling units count towards the players supply.