The original Legion appears during the Celestial Madonna storyline in the titles Avengers and Giant-Size Avengers, having been summoned from time by the villain Kang the Conqueror to kill the superhero team. As the name implies, the members of the Legion were all characters established as being deceased in Marvel continuity, being pulled from time a moment before their deaths. Although partially successful in their mission, the Legion frees itself from Kang's control and aid the Avengers. Kang flees when confronted by the Thunder GodThor, with Immortus reviving Iron Man and healing the Vision and returning the Legion back to their respective eras. Only the Human Torch android is allowed to remain as it is revealed that the character is in fact the Vision, years before being modified by the robotUltron.
Legion of the Unliving II
The second version of the Legion is featured in an Avengers annual, in which the Elder of the Universe the Grandmaster, usurps the power of the entityDeath. Intending to destroy the universe -- via six bombs -- and recreate it with his fellow Elders, the Grandmaster decides to eliminate opponents the Avengers by having fellow Elder the Collector take the heroes to the Realm of Death to battle the Legion of the Unliving. A battle to the death follows, and when Thor observes fellow Asgardian the Executioner act dishonourably he realizes the Legion are in fact only copies of the original beings, minus their personalities. Almost all the Avengers are killed stopping the Legion and defusing the bombs, with only Captain America and Hawkeye surviving. The Grandmaster then proposes another competition and adds the fallen heroes to the Legion, until tricked by Hawkeye in a game of chance. Losing the game disorients the Grandmaster and Death is released, with the entity banishing all the Elders from its realm, restoring all heroes to life and then returning them to Earth.
Legion of the Unliving III
The third version of the Legion appears in the title Avengers West Coast, and is created by reoccurring Avengers foe Immortus. Seeking to use the Scarlet Witch as a point from which to control all of time, Immortus summons the Legion to delay the pursuing Avengers, although they are almost totally defeated by the heroes. Immortus himself is judged by the entities the Time Keepers and forced to become the nexus himself.
Legion of the Unliving IV
A fourth version appears in the title Avengers, with the former villains' spirits summoned and placed in the bodies of dead civilians -- effectively zombies -- by Avengers foe the Grim Reaper who mistakenly believes the Avengers had murdered him. When the character is confronted by the Vision and forced to accept that he actually committed suicide, the Legion rebel. Grim Reaper panics and is attacked and apparently consumed by Lloigoroth, with the Legion's spirits departing the corpses.
Legion of the Unliving V
The fifth version of the Legion appears in the third volume of the title Avengers, with the returning spirit of the Grim Reaper corrupting his brother Wonder Man and using him to summon former Avengers who died in battle. The Scarlet Witch, however, uses her love for Wonder Man to free him from the limbo-like state his ionic form was in, thereby freeing him from the Reaper's control. Wonder Man is then able to restore the Reaper to a physical form. The humbled villain relinquishes control of the Legion, and the dead heroes speak to their comrades a final time before dying once again.
Legion VI
A new Legion is created by Colonel Shadow in his vampire civil war, whose membership includes a bat-like vampire named Carpathian, Baroness Blood, Boy-Thing, Rat Bomber, Snowsnake, and his dog Sarge.
