Resurrection

Resurrection is the paracausal ability of coming back to life after death.

Guardians
Main article: Ghosts

Ghosts are small, sapient machines created by the Traveler shortly after the Collapse. Their sole purpose is to locate and resurrect deceased individuals capable of wielding the Light as Guardians, and to support their Guardian charge in combat.

Hive
During the war with the Ecumene, the King of the Hive Auryx came to realize that the Worm had deceived him and his sisters: their Worms appetites were growing past their ability to feed with death. Meeting with his sisters in his ascendant realm, surrounded by their servants (some of which despised them for showing weakness) they despaired over their dilemma. When his sisters offered their power to help Auryx find a way to save them, Auryx killed them, then used that power to confront his patron god Akka, the Worm of Secrets. He killed Akka so that he may steal its ability to call upon the Deep and created the Tablets of Ruin, which gave him the power to Take. His transformation complete, Auryx was now Oryx, the Taken King. During the subsequent war with the Ecumene, Oryx revived Xivu Arath in an act of war, and revived Savathûn in an act of cunning.

Shortly after the SIVA Crisis, Omnigul would make a brief return to Skywatch after having "undone" her death to continue her work, only to be swiftly killed again by the Guardian and their fireteam. Since Omnigul was capable of evading permanent death, Ikora remarked that the Vanguard will likely continue to face Omnigul as many times as it takes.

Before the Warmind (expansion), other blasphemous acts of defying death could be seen in the adventure Deathless on Titan, where Savathûn's Brood Necromantis repeatedly killed and resurrected Takul-Dar, the Unbreakable.

Necromancy is a practice involving the use of paracausal abilities to resurrect the dead. It is considered by Oryx's Hive to be a violation of The Sword Logic, and therefore forbidden; however, it has been employed by the heretical Hive Prince Nokris, who was taught the secrets of necromancy by the Worm God Xol. Xol himself used necromancy to resurrect several individuals of various races who had been slain by the Guardians, including Valus Ta'aurc, Drevis, Wolf Baroness, and Urzok, the Hated, before Taking them and converting them into Ta'aurc, Aspect of War, Drevis, Aspect of Darkness, and Urzok, Aspect of Hate respectively. Many of Savathûn's Hive have the title "Revenant" attached to their names, suggesting that Savathûn and her subordinates also employ necromancy.

When Besurith, Voshyr and Kinox efforts at resurrecting Crota and Oryx proved in vain, Kinox saw an opportunity to rally the leaderless Hidden Swarm by reanimating the deceased Zulmak as their puppet champion, with Hashladûn offering the phantasmal essence of the Nightmares as a catalyst to infuse into Zulmak's husk recovered by Besurith and Voshyr, creating the first hybrid of a Hive infused with the power of the Nightmares.

Scorn
Dark Ether is a corrupted variant of Ether used and manufactured by the Scorn from Fikrul's body. Created when Riven granted Uldren's wish to resurrect a dead Fikrul by infusing Fikrul's Ether with Uldren's own Taken essence,  this substance is the source of the Scorn's strange powers. Fikrul can use the substance to resurrect dead Eliksni and Scorn, including himself, while the Machinist can do the same from Ether Rituals.

Resurrected individuals appear to be able to survive without a head, as shown by Ravagers and Abominations. Repeated resurrections have a physical toll on the user, leading to the progressive formation of tumor-like growths and increasing mental derangement. Eventually, Eliksni who have undergone many resurrections will become Screebs, mindless, crawling Thrall-like monstrosities who throw themselves at enemies and self-destruct in a blast of Dark Ether.

Nezarec
The Disciple of the Witness known as Nezarec has returned from death on at least one occasion, after having been slain by Savathûn during the Collapse. In this particular case, he was resurrected by the Traveler's Light, which had blasted open the Pyramid where his severed head was being stored. He is implied to have died and been resurrected prior to this, as he reflected upon having "welcomed death" several times before.