Psi blade

The psi blade, also called the psionic blade or psi-blade, was a type of energy blade manifested through the use of psionic power. It was the signature close-combat weapon of the protoss, wielded above all by the zealots, who channeled their psionic energy through focusers mounted on their forearms. Incandescent and capable of cutting through almost any material, the psi blade defined protoss melee warfare, gave rise to the dark templar warp blade, and was imitated in modified form by terran scientists working from captured protoss technology. (StarCraft (manual); StarCraft II: Legacy of the Void)

Protoss psi-blades#

A protoss generated psionic energy that was contained and channeled by psi-blade focusers, mounted on forearm units fitted to the power armour worn by zealots. Executor Tassadar was able to channel his psionic power into blades without the need for forearm units, and could even extend his psionic blade into a whip-like form to strike distant targets. Psi-blades were incandescent and usually of a blue-white color, and could cut through almost any material regardless of density, though they could be parried by other psi-blades and by warp blades. Because the blades cauterized as they cut, combat among protoss was generally bloodless. Over time the Khalai refined psi-blade focuser construction so that a blade could grow in power as a zealot's fury mounted in the heat of battle. (StarCraft (manual); StarCraft: Shadow of the Xel'Naga; StarCraft: Queen of Blades; StarCraft Field Manual; StarCraft II: Legacy of the Void; Zealot Science; One People, One Purpose)

The warp blade and other variants#

The Nerazim refined the psi blade into the far more powerful warp blade by infusing it with both Void energy and their own burgeoning psionic power. After the severing of his nerve cords, Artanis demonstrated the ability to wield a psi-blade and a warp blade in tandem. After the fall of Aiur, some Khalai protoss adopted the way of the Nerazim and returned to wage a secret war against the Zerg, wielding psionic scythes, which were modified forms of the psionic blade. (StarCraft: Brood War (manual); StarCraft II: Legacy of the Void)

The color and character of psi-blades varied across the protoss factions. The Zhakul Guardians manifested green psi-blades while under the control of Maar. The Purifiers' blades ranged from blue-white to yellow and yellow-orange depending on the program and era. The Tal'darim possessed red psi-blades, called bane blades, which were drawn as pure Void energy from Amon's domain rather than the pure psionic energy of Khalai blades or the mixture of Void and psionics found in the dark templar's warp blades. Ancient Tal'darim legend spoke of masters who could use these blades to tear planets in half, and protoss possessed by Amon, including Artanis and Selendis, as well as Emil Narud, were able to manifest red blades of their own. (StarCraft II: Wings of Liberty; StarCraft II: Heart of the Swarm; StarCraft II: Legacy of the Void; Ascension)

Terran psi-blades#

The psi blade was not exclusive to the protoss. The terran/protoss hybrids of Project Gestalt demonstrated the ability to use psionic blades. A related weapon, the monomolecular blade, used its wielder's psionic energy to hone an edge sharpened to a microscopic degree, allowing it to cut through both physical armor and energy shields. Working from captured protoss technology, Terran Dominion scientists developed similar devices for use by ghosts and comparable soldiers, giving the terrans their own psionic blades adapted from the protoss original. (StarCraft: Frontline Volume 3; StarCraft II: Nova Covert Ops)