Dark archon (StarCraft II)

Legacy of the Void
Dark archons are the Nerazim psionic attacker, with the and ascendant serving as alternatives. Dark archons are produced directly from the gateway instead of merged from dark templar, but selecting them as the psionic attacker unit prevents the player from using high templar, and by proxy, normal archons.

Though the dark archon deals less damage than the normal archon, it still deals a lot of damage and deals splash damage to clumped enemies. Its abilities are more supportive than the high templar and ascendant, making the dark archon a unit that demands less micromanagement in return for being less effective offensively without the psionic skills of the others.

An important note when using the dark archon's mind control is that it no longer drains the dark archon's shields, and controlled units do not count towards the player's supply. If the player takes control of an SCV or drone, they cannot build structures, but SCVs can Repair the player's protoss mechanical units and structures. Heroic units, including all hybrid, are immune to Mind Control.

Quotations

 * see: StarCraft II Dark archon Quotations

Co-op Missions
Dark archons are available when Vorazun is selected in the Co-op Missions mode of Legacy of the Void. They may be warped in from the gateway, and are upgraded at the dark shrine.

Development
Dark archons did not return in StarCraft II: Wings of Liberty and StarCraft II: Heart of the Swarm. Instead, dark templar merged into standard archons. The game's data files include assets for an unused/unfinished dark archon unit, including a texture and and possibly data for abilities. The texture depicts a humanoid body with nerve cords; the latter is unusual for Nerazim.

Some artworks suggest initally the Dark Archons was used by Tal'darim, but they do not appear in the game. Data in the game suggests that originally, Tal'darim blood hunters would merge into dark archons. In the final product, normal Tal'darim archons use the dark archon model.