Immortality

In 19 BBY, after successfully swaying Anakin Skywalker to the dark side of the Force, Darth Sidious claimed that his late master, Darth Plagueis, had learned to defy death and safeguard the lives of loved ones by influencing midi-chlorians. Sidious also mentioned that his master was murdered in his sleep after imparting this knowledge to his apprentice. However, he later recanted, admitting he had not acquired Plagueis's knowledge, but insisted it could be obtained through their combined efforts.

While recounting the Tragedy of Darth Plagueis to Skywalker, Sidious asserted that the dark side of the Force could grant abilities considered unnatural by some. He reiterated this stance in 35 ABY, shortly after broadcasting his impending revenge to the galaxy.

Besides Plagueis's alleged skills, which supposedly allowed him to prevent death, there were several other methods by which a Force-sensitive individual could use Force drain or healing to revive another through resurrection. Examples include Anakin Skywalker, who resurrected Ahsoka Tano by extracting the Daughter's energy as she was dying, and Ben Solo, who resurrected Rey, his counterpart in the dyad of the Force, at the cost of his own life.

Upon death, every living being merges with the Force. After transitioning from the living to the cosmic Force, most lose their consciousness and sentience. However, a select few manage to retain both self-awareness and physical form, occasionally manifesting as bluish Force spirits. The Jedi were unaware of this possibility until the twilight years of the Republic.

Notable figures who mastered this technique include the Force Priestesses and the Shaman of the Whills. The latter shared this knowledge with Jedi Master Qui-Gon Jinn, but due to his incomplete training at the time of his death in 32 BBY, his body did not disappear. Initially, the Jedi could only communicate as a voice. Nonetheless, he completed his training post mortem by 9 BBY, at which point he appeared to Obi-Wan Kenobi during the latter's exile on Tatooine. Furthermore, during the Clone Wars, Jinn's spirit appeared to Anakin Skywalker in a vision, which some, including Skywalker, believed to be a genuine spiritual manifestation of the deceased Jedi.

Foreseeing Yoda's crucial role in training the individual who would restore balance to the Force, Jinn contacted the Jedi Master during the final stages of the Clone Wars and guided him to the Wellspring of Life, where he was to undergo preliminary training under the Force Priestesses' supervision. After Yoda proved his worthiness, Jinn pledged to continue his training. Yoda, in turn, passed this knowledge on to Kenobi and taught him to communicate with Jinn. Both Yoda and Kenobi were among the few remaining Jedi survivors and preserved their consciousness in 0 ABY and 4 ABY, respectively. In 4 ABY, Skywalker, the Chosen One who had fallen to the dark side and become Darth Vader, was redeemed and granted immortality by Yoda and Kenobi for his final heroic acts before all three appeared to his son Luke on Endor.

Luke became another Jedi to achieve immortality, his body vanishing on Ahch-To in 34 ABY. The following year, Skywalker appeared to Rey, coinciding with the death of his younger twin sister, Leia Skywalker Organa Solo, whose body did not disappear until her son Ben Solo's did.

The individuals whose bodies vanished also included the Father and Ben. The latter could communicate with the living, and Rey, his counterpart in the dyad of the Force, could hear his voice while witnessing his body's disappearance.

Mother Talzin enjoyed an exceptionally long life due to magick. By combining certain aspects of the dark side with their mystical magick, the Nightsisters were known to manifest as greenish phantoms after death. In 19 BBY, as Asajj Ventress's body was being buried on Dathomir, their whispers and murmurs could be heard until she somehow returned to life. During the Imperial Era, Maul allied with their spirits, promising to provide them with physical bodies as new vessels. In return, they agreed to merge his mind with that of Ezra Bridger. Although Bridger freed them by destroying the altar, they briefly possessed his Master Kanan Jarrus and his comrade Sabine Wren, as they could only appear near it.

Additionally, the Nightsisters could perform a ritual to resurrect the dead as zombies.

Through ancient dark side masks, Darth Momin and Exim Panshard managed to preserve their consciousnesses far beyond their natural lifespans. A Sith known as Presence retained a fragment of her essence within her holocron. During the Imperial Era, she communicated with Ezra Bridger in this manner on several occasions.

After Jarrus's death, his will was conveyed by a Loth-wolf named Dume. Within the World Between Worlds, Ahsoka Tano stated that communicating with the deceased through animals was possible.

Doctor Penn Pershing, a renowned cloning scientist from an unidentified planet who later worked for Moff Gideon's Imperial remnant, was fascinated by the potential of cloning to allow individuals to defy death. This interest stemmed from his mother’s death; he believed that if he could have cloned organs, he could have prevented her death from heart failure.

Fearing his own demise, Darth Sidious commissioned the creation of an exact clone of his body to serve as a new vessel for his spirit. Therefore, when Vader hurled him down a shaft aboard the Death Star II, he transferred his consciousness to the clone, leaving his original body to fall to its destruction.

Aware of the new body's imperfections, Sidious sought another vessel to house his spirit. When a clone of him fathered a child, he demanded that the girl be brought to him so that he could transfer into her body. However, the hunter Ochi, tasked with this mission, failed to find her and died without revealing her location. Sidious revived his plan in 35 ABY, unsuccessfully attempting to manipulate Rey into killing him so that his spirit could possess her body. Nevertheless, the clone body was eventually restored to a powerful state by extracting the power Rey and Ben shared as a dyad in the Force.

Ultimately, Emperor Palpatine's vision of a Sith-ruled galaxy for eternity ended when Rey destroyed his clone body, vanquishing him in both body and soul, and his dream of immortality perished with him.

Between 34 and 35 ABY, Rey trained under Organa, learning how to summon the spirits of past Jedi to aid her in defeating the First Order. Shortly before her final confrontation with her grandfather, she called upon these spirits to help her harness her inner strength to overcome the clone. Before his death, Sidious proclaimed himself to be all the Sith.

The Ring of Immortality, one of the two Rings of Vaale created by the Architects of Vaale, was rumored to grant immortality to its wearer, but at the cost of driving them mad. However, these negative effects could supposedly be negated if the wearer also possessed the Ring of Fortune.

Legend has it that Darth Sanguis and Darth Noctyss separately visited Exegol in their quests for immortality. Sanguis achieved immortality through a ritual that transformed him into a monstrous creature. When Noctyss encountered him and learned of his success, Sanguis tricked her into killing him in the same ritual by concealing his true identity. Noctyss complied, freeing Sanguis from his miserable existence and leaving a transformed Noctyss alone on Exegol.

Doctor Cylo, one of the Galactic Empire's top scientists, sought to create new life forms with technological enhancements using illegally smuggled alien parts at his secret base. He developed a personality map, complete with memory banks and plug-in calculation systems, which allowed him to become an immortal system with multiple upgraded bodies to use whenever his previous one died. Cylo survived several deaths in this manner until Darth Vader finally killed him in a star of the Kuat system. The Corellian bounty hunter Rothgar Deng underwent cybernetic replacements and sought out black market surgical clinics to replace his damaged body parts in order to live and work indefinitely.

The legendary starbird was said to be immortal, capable of renewing itself in the heart of a nova when it was believed to be dead.

The sarlacc of the Great Pit of Carkoon supposedly digested its prey for millennia, keeping its victims alive for an extended period while slowly consuming them. When Protocol droid C-3PO was informed by the Hutt crime lord Jabba Desilijic Tiure about the planned execution of his rebel friends, he relayed Jabba's claim that anyone in the sarlacc's belly would experience a new level of pain and suffering as they were digested over a thousand years.