The Deviant, or Rogue templar, is a psionic casters specializing in forbidden techniques.
With Psionic Storms tearing apart space and time, High Templars are perhaps one of the Protoss' most powerful psi users next to Archons. Due to their intense training in Khala, Terran Resocialization techniques and Zerg infestation have only a handful of success in "converting" certain specimens. Because of this, the Protoss believe themselves almost invincible to any known form of brainwashing other than their own Mind Control techniques. What they do not know is that the Vaul have records on how far the Xel'Naga taught the Protoss in the ways of Khala, which includes the limits to the Protoss' mental barriers. With this data, the Vaul began cloning specimens of the most powerful High Templar lost in the First and Brood Wars. Using psionically enhanced resocialization technology, the Vaul developed powerful Deviants loyal only to them.
Although the Xel'Naga taught the Protoss multiple psionic techniques, they did not complete their teachings before leaving them to complete their other plans. Some of these techniques were so dangerous, they were forbidden from ever being taught to anyone or anything. With the inevitable return of the Fallen One, such limitations were irrelevant, so the Deviants began learning Forbidden abilities.
One such ability is a much more unstable version of the Psionic Storms called Firestorms. Like the regular ones used by High Templars, Firestorms damage everything in them with crimson lightning. Unlike regular Psionic Storms after the lightning stops crackling, the attack leaves everything that touched it in flames of psionic energy. Nothing stops the flames from burning until either the target is destroyed or the flames burn themselves out (Naruto: Amaterasu). Should an allied unit even try to save the affected ones, they would be engulfed in flames themselves making rescue attempts all but impossible. Originally believed to be used in rituals that separated the strong from the weak. The Xel'Naga forbade this technique due to the high mortality rate and difficulty of control.
As part of their training, the first batch of Deviants were sent to an interdimensional realm devoid of light and filled with ferocious beings made of psionic energy (DC Comics: Phantom Zone). There, they were forced into Gladiatorial combat using advanced Feedback techniques to survive. If any were too weak to go on, they would be drained of their life-force by the extradimensional beasts until nothing but a husk remained (Stargate - Atlantis: Wraith and Shadow creature). After training was complete, those who survived mastered the technique to turn any energy using being into an EMP Bomb. Of the 300 specimens in the first batch, only ten survived long enough for researchers to refine the process. Despite the low survival rate, the remaining subjects of the training are some of the most powerful, albeit "mildly unstable", Templars in existence (Star Wars: Sith).
Like their High Templar counterparts, Deviants are also able to combine with other templars to form a Chaos Archon, Making them an asset in heavy psionic support roles.
- FIRESTORM - deals 80 damage in an area for a period of time. Both ground and air units are affected no matter what affiliation. Once finished, it leaves units in purple flames that deals 4 damage for 30 seconds. Flames can not be stopped until 30 seconds are over. Other units catch on fire if they get close to affected units
- NEGABURN - target unit receives damage equal to energy siphoned. Affected unit also sends out an EMP Surge reducing shields and energy to 0 for any ally or enemy in the blast radius
- Archon Warp - merges with another Deviant or Venator to summon a Chaos Archon