The Force power known as dark illusion granted its user the capability to shape Force visions into weapons aimed directly at a chosen target. To conjure dark illusion, an age-old Sith practice was employed, requiring both a Force-bond connection originating from an individual linked to the target and the recitation of a Sith enchantment in the archaic Balc language. Further enhanced by the blood of the bonded person, Force lightning, and the energies of the dark side of the Force, dark illusion could reach its designated victim regardless of their location within the galaxy.
During the galactic conflict referred to as the Clone Wars, the Dark Lord of the Sith, Darth Sidious, employed dark illusion to assault Grand Master Yoda of the Jedi Order, capitalizing on the bond between Yoda and his Sith apprentice, Darth Tyranus, for the ritual. By also drawing upon the power emanating from the tomb of the long-deceased Sith Lord Darth Bane, Sidious, while situated on Coruscant, managed to reach Yoda on Moraband, the ancient homeworld of the Sith.
Dark illusion, a Force power, emerged from the depths of the dark side of the Force. This power empowered its user to manipulate Force visions to impact a specific target. The utilization of dark illusion necessitated an ancient Sith ritual. This involved the blood of a Force-sensitive individual possessing a Force-bond with the intended victim. The bonded individual was required to concentrate on their connection with the target. Once the blood was extracted, it had to be combined with a surge of Force lightning within a sacrificial altar basin. An ancient Sith incantation, spoken in the Balc language, finalized the ritual. Subsequently, immersing one's face in the empowered basin granted access to dark illusion. The resulting Force visions could be employed to replicate specific individuals, mirroring their physical attributes and vocal characteristics. The illusion could be augmented by a source saturated with dark side energy, potentially leading the target to believe they were in an alternate location during these visions.
The technique of dark illusion was an ancient one, known only to a select few Sith. When Darth Sidious, the Dark Lord of the Sith, detected Jedi Master Yoda's presence on Moraband, the ancient Sith homeworld, he sought to understand the Jedi's reasons for being there and to undermine the Grand Master's resolve. Consequently, he invoked the power of dark illusion, utilizing his sacrificial altar basin from a hidden location on Coruscant. As Yoda ventured into the tomb of Darth Bane, an ancient Sith Lord from millennia prior, Sidious further amplified the dark illusion's potency by tapping into the tomb's power, which had previously served as a Jedi sacrificial chamber in past centuries. This empowerment enabled Sidious to tempt Yoda with familiar scenarios within the ensuing visions. Ultimately, Sidious aimed to dominate the galaxy, but upon Yoda's rejection of the Sith Lord's temptations and visions, he realized that more time was needed before the Jedi could be overcome and the Sith could reclaim their power.
During the Clone Wars, a conflict that fractured the galaxy and divided the Galactic Republic, the Sith Lord Darth Sidious and his Sith apprentice, Darth Tyranus, employed the ritual to summon the power of dark illusion. Sidious meticulously concealed his Sith identity, operating as the Republic's Supreme Chancellor Palpatine, as did Tyranus, publicly known as Count Dooku, the leader of the Separatist Alliance. Upon sensing Master Yoda, Dooku's former mentor, on the planet Moraband, Tyranus was summoned to Coruscant to consult with his Sith Master.
Within an abandoned industrial district of Coruscant known as The Works, Sidious informed his apprentice of their intention to exploit Dooku's Force-bond with Yoda, established during their time within the Jedi Order, to ascertain Yoda's purpose on Moraband and to break his will. Prior to Yoda's arrival, only Jedi Council member Ki-Adi-Mundi suspected the Sith's ability to exploit Yoda's bond with Dooku. Over a sacrificial altar basin, Sidious drew Dooku's blood with a knife, allowing it to drip into the water-filled basin, and recited the Sith incantation in Balc. Together, the Sith Lords channeled Force lightning into the basin, and as Tyranus focused on his bond with Yoda, Sidious harnessed the power of dark illusion. When Tyranus expressed concern about Yoda sensing their presence, Sidious reassured him that he would appear to Yoda as a familiar face, as he immersed his face into the sacrificial altar.
Sidious, through his vision to Yoda, masqueraded as the long-dead Jedi Master Sifo-Dyas, imprisoned within the tomb and sacrificial chamber of the ancient Sith Lord Darth Bane. Sidious tempted the old Jedi Master with an opportunity to finally uncover Darth Sidious's true identity, as the Jedi were only aware of his existence. Upon Yoda's refusal, Sidious further entranced Yoda by utilizing the tomb's power to enhance his illusion, leading the Jedi Master to believe he had returned to Coruscant. Yoda found himself in the presence of Jedi Knight Anakin Skywalker and a squad of clone troopers from the Grand Army of the Republic's 501st Legion, engaged in the ongoing pursuit of both Dooku and Sidious within the Works. As the Jedi cornered the two Sith Lords in the illusion, the 501st troopers were swiftly incapacitated, and Skywalker, in turn, beheaded Dooku as Yoda pursued the hooded Sidious. The two briefly dueled before the vision of Sidious threatened to kill Skywalker while simultaneously attacking Yoda with Force lightning. The Jedi Master was then faced with a choice: to uncover the Sith Lord's identity once and for all or to save Skywalker, whom Sidious had thrown off a catwalk. Yoda chose the latter, sacrificing himself and falling into the depths of Coruscant with the vision of Sidious as the dark illusion dissipated.
Following the illusion's cessation, Sidious emerged from the altar basin and informed Tyranus of their failure to break Yoda's will, stating that more time was needed to defeat the Jedi. Unbeknownst to either Sith, Yoda had undergone a trial by the ethereal Force Priestesses to learn the secret to immortality, succeeding upon defeating the dark-siders encountered, including Sidious's own dark illusion. Furthermore, despite Tyranus' presence throughout the ritual, Sidious alone controlled the visions presented to Yoda, leaving Tyranus unaware of the foreshadowing of his own death or Skywalker's eventual fall to the dark side. Near the Clone Wars' end, Skywalker killed Dooku in the same manner he had slain the count within Sidious's dark illusion. Dooku's death marked one of Skywalker's initial steps toward becoming Darth Vader, Sidious's new Sith apprentice, preceding the Great Jedi Purge, which fulfilled Sidious's plot for the revenge of the Sith.
The dark illusion Force power made its debut in "Sacrifice," the thirteenth episode of The Lost Missions, released as the sixth and final season of the Star Wars: The Clone Wars television series. Dark illusion was first officially named in the "Sacrifice" episode gallery on StarWars.com. In the episode's script, the Sith incantation spoken by Sidious was labeled as "Balc speech" and written as "Kintik hadzuska sutta chwituskak! Kintik hadzuska sutta chwituskak! Jiaasjen Jidai, jiassjen Jidai!". Tim Curry provided the voice for Darth Sidious, who recited the Sith incantation in Balc to summon the power of dark illusion.