Transference was a dark side power that a Force-sensitive used to transfer their spirit and consciousness to a different body through the Force. The wielder of this ability could also utilize it to prevent the deaths of other beings. It was discovered through the Sith Order's ultimate goal of attaining immortality, with the Sith Lord Darth Plagueis becoming the first to harness the power of transference. Despite this, however, Plagueis was killed by Darth Sidious, his Sith apprentice. Sidious used his Sith Master's methods to transfer his consciousness to a clone of his original body, which was destroyed during the Battle of Endor. He tried again to relocate his spirit to a new body, that of his granddaughter Rey, during the Battle of Exegol, but failed.
Transference was a Force power that was harnessed through the dark side of the Force by a Force-sensitive. Through the Force the user of transference could send their consciousness and spirit into another corporeal body, the biological conditions of which determined its viability as a host for the Force user's spirit. Artificial host bodies such as Strand-Casts and modified clones failed to adapt to the power of the dark side affixed to the transference user's consciousness, consequently resulting in rapid decay, physical deformity, and ultimately death. Additionally, the new body could experience debilitating side effects of a rushed or imperfect transference process. The variables that increased the adequacy of a potential host included reproduction, a strong connection to the Force, and a hereditary connection to the user of transference.
The purpose of transference was to prevent the permanent death of a Force-sensitive. While the physical body of the Force-sensitive would still ultimately die, through transference their consciousness was able to remain intact by inhabiting a new host, essentially resurrecting the Force-sensitive. As such, transference was regarded as a form of immortality by the Sith. In addition to preserving the consciousness of the user of transference, the power could be harnessed to preserve the lives of other beings.
The Sith Lord Darth Plagueis discovered the power of transference, succeeding where his predecessors failed. For centuries generations of Sith Lords unsuccessfully tried to gain immortality through the dark side of the Force, unwilling to accept death as the conclusion of one's physical existence, as believed by the members of the Jedi Order. Plagueis was a wise and powerful Dark Lord of the Sith; his knowledge of the Force was vast, according to his Sith apprentice, Darth Sidious who stated that his Sith Master could influence the midi-chlorians to "create life" as well as prevent the deaths of other beings.
As powerful as Plagueis was though, he did not survive his own death despite possessing the ability of transference. Plagueis was killed in his sleep by his apprentice, Sidious who used his master's trust as an opportunity to replace him under the tradition of Darth Bane's Rule of Two. Plagueis had not anticipated his apprentice's betrayal and consequently lacked sufficient time to preserve his consciousness after his physical death. Sidious, having claimed the mantle of the Sith by killing his master, swore to never suffer the same fate as Plagueis.
Like his predecessors, Darth Sidious coveted the secret of eternal life. Determined to avoid his master's fate, he secretly devoted his reign as Galactic Emperor to ensuring his survival after death, a plan which relied on both Plagueis' teachings as well as the loyalty of the Sith Eternal cult. Utilizing the ancient Sith planet Exegol as a base of operations, Sidious' Sith cultists experimented on his genetic template to create a modified clone that could replace the Emperor's original body in the event of his demise. That time had come sooner than Sidious had anticipated, but he was successful in preserving his consciousness nonetheless. Having long sensed a remnant of the light side of the Force within his apprentice, Darth Vader, Sidious had planned his revival by the time his death came at Vader's hand in the Battle of Endor. Vader perished as well, and with his demise Darth Bane's Sith lineage was destroyed, fulfilling the prophecy of the Chosen One.
The power of transference succeeded in moving Sidious' spirit to the clone body that had been prepared for him on Exegol. As a result, the Emperor was effectively "reborn" as the Galactic Empire collapsed by the end of the Galactic Civil War. Though his consciousness remained intact, his connection to the dark side was too powerful for his new body to contain, leading to numerous deformities and forcing Sidious to rely on an Ommin harness for life support.
In order to preserve Sidious' essence and legacy, the Sith Eternal resorted to using modified cloning techniques, such as Strand-Casting, to create a more stable host from their master's template. Despite honing their skills as cloners through years of experimentation within the dark science laboratory of the Sith Citadel, their efforts failed to provide Sidious with a replacement for the imperfect clone that his spirit inhabited. The strandcast known as Snoke was considered an "unworthy vessel" by Sidious, who nonetheless saw his creation's value as a proxy Supreme Leader for the First Order, as well as a mentor for Vader's grandson Kylo Ren. Another strandcast that was partly modeled on Sidious' template was his cloned son; the clone possessed sufficient health yet failed to inherit his father's connection to the Force.
Sidious disdained the existence of his son, whom he regarded as a "creature" that was ordinary and useless. However, he surmised that the clone would prove useful due to his inherited connection to the Palpatine bloodline and therefore permitted his survival until a "genetic heir" could be produced through natural conception. The Emperor's son ultimately sired a daughter, Rey who had inherited the powerful Force-sensitivity of her grandfather. For this reason as well as her strength in the Force, Sidious concluded that his granddaughter was the ideal host that would ensure the preservation of his essence and the Sith legacy. However, she was hidden by her mother and father who sought to protect Rey from the Emperor.
The clone body of Sidious was on the verge of complete decay as he announced his return to the galaxy at the time of the First Order-Resistance War. By then, Rey had resurfaced in the greater galaxy after years of living in isolation on the desert world of Jakku. Unaware of her secret lineage, she had sided with the Resistance while also endeavoring to learn the Jedi arts under Vader's twin children, Jedi Master Luke Skywalker and Ren's mother General Leia Organa in turn. While Sidious had influenced Kylo Ren's progress as a dark-side apprentice and heir to the Sith legacy in the form of the Final Order, he continued to regard Rey's body as the ideal vessel due to her power and heritage as a Palpatine.
Sidious succeeded in luring Rey to Exegol where he urged her to claim the Throne of the Sith as "Empress Palpatine," declaring that his spirit would transfer into her once she killed him in hatred and anger. In truth, he planned to transfer his spirit into her body. He conducted the process of transference as a Sith ritual, which was witnessed by an audience of his followers in the Sith Eternal. The ceremony coincided with the Battle of Exegol; the threat of her allies' destruction and the seductive power of the dark side almost compelled Rey to submit to her grandfather's demands, but she ultimately resisted his influence with the help of Ben Solo, who had returned to the light side by renouncing the persona of Kylo Ren. Rather than completing the ritual by killing Sidious with her lightsaber, as Sidious had intended, Rey transferred the Skywalker lightsaber to Solo through their Force-bond, denying Sidious the opportunity to the body of his granddaughter.
Though Sidious failed to transfer his consciousness to Rey, he discovered that his granddaughter and Vader's grandson were connected as a dyad in the Force, making their bond uniquely powerful as described in the Doctrine of the Dyad. Through the dark side he drained them of their combined life force to restore his own strength, which also healed his decaying clone body. Ultimately though, he was both physically and spiritually destroyed permanently when his own Force lightning attack was reflected in his direction by Rey, who was aided through the Force by Jedi spirits.
Transference first appeared as a Sith ritual in Star Wars canon in the 2019 film Star Wars: Episode IX The Rise of Skywalker, the third and final installment of the Star Wars sequel trilogy, and was first identified in the 2021 reference book Star Wars: The Secrets of the Sith. The ritual was based off of Transfer essence, which was originally first mentioned in Star Wars Legends in the comic Dark Empire 2, written by Tom Veitch which was released on February 18, 1992, and first appeared in Dark Empire 5, which was authored by Veitch, penciled by Cam Kennedy, and released on August 18, 1992.
- Star Wars: The Secrets of the Sith
- Star Wars The Dark Side Pocket Expert