Written by Bob Harras, The Gathering Saga ran through The Avengers comic between 1992 and 1994. It dealt with the Avengers battling alternative Earth versions of themselves.
Debuting in Avengers Vol. 1 #355, The Gatherers (Sloth, Cassandra, Magdalene, and the Swordsman) all came from alternate Earths on which Sersi went mad and killed everyone. On their alternate Earths, they were Avengers. They were each the last survivor of their own world and were recruited by Proctor to destroy Sersi and the Avengers of Earth-616. In some, but not all cases, the Gatherers would not cope well with the transition between dimensions, and to exist in Earth-616, their counterparts in the Earth-616 reality had to be killed through a process called a “gathering” so that the Gatherers themselves could live. In this case The Gatherers rescue the Coal Tiger from a parallel universe, but to keep him alive they must destroy the Black Panther.
Elsewhere, Sersi and the Black Knight begin an uneasy romance, much to Crystal’s disappointment. Black Widow plays the matchmaker and sets up Hercules with Taylor Madison but they are interrupted when The Gatherers invade Avengers mansion to get information on the Black Panther, but the Avengers are prepared. Unfortunately, the Gatherers are victorious and make their way to Wakanda.
In #356, The Gatherers travel to Wakanda where they overwhelm the Black Panther. Fortunately, the Avengers assist but The Gatherers keep the Avengers at bay long enough with Magdalene incapacitating the Vision, Sloth temporarily defeating Hercules, and Cassandra taking down Sersi. Cassandra then began to “gather” the Black Panther so that the Coal Tiger might live. The Coal Tiger though, convinces the Swordsman to let him die an honourable death and let the Black Panther live. The Swordsman rebels against his teammates. Wakandan soldiers force The Gatherers to flee, but the Avengers prevent the Swordsman from leaving.
The Avengers learn more about the Gatherers from the Swordsman in #357 and they also learn about the parallel universe he comes from. The Avengers enjoy a bit of down time and attend the Black Widow gala dinner. Unfortunately, it’s interrupted by the Watcher who has an ominous warning for them.
In #358 Magdalene begs Proctor to allow the Gatherers to rescue the Swordsman, Proctor ordered the Gatherers on another mission to yet another dying Earth. On this Earth, Proctor claims that the Gatherers would find a new recruit that would rescue the Swordsman. In reality, the Swordsman has gained too much knowledge and had become dangerous to Proctor, who intended not to recruit a new Gatherer to aid the Swordsman, but actually to murder him and in #359 releases Tabula from stasis in order to assist in his plan to do that. Meanwhile, The Gatherers managed to defeat an alternate form of the Vision and bring him to Proctor, although they sustained injury to themselves in doing so.
In #360, The Gatherers lay a trap for the Vision of Earth-616, in which Tabula takes the form of Laura Lipton, the wife of the man whose brain patterns were the basis for the Vision’s computer mind. While Tabula distracts the Vision, The Gatherers attack him from behind and capture him. Proctor then had his newest gatherer, an alternate counterpart of the Vision, switch bodies with the Vision of Earth-616 and infiltrate the Avengers and kill the Swordsman when he has the chance. The Vision of Earth-616 attempts to escape in #361 but is recaptured by Proctor. In #362 The false Vision is discovered by the Avengers, who force him to lead them to Proctor.
In #363 it is revealed that many years ago Proctor found Ute, the Watcher of Earth’s solar system in an alternate reality, broken and nearly dead after he came to that Earth to observe its final moments, and instead became a victim of its fate. Proctor took Ute and used his powers to seek out the worlds that would yield him his Gatherers.
In the present, The Gatherers are torturing The Vision of Earth-616 whilst The Vision of the Gatherers leads The Avengers to Proctor’s base in the Andes mountains. The Avengers launch a surprise attack on The Gatherers. Proctor almost kills The Vision of the alternate Earth for leading the Avengers to him.
Proctor reveals that Sersi has destroyed the Earth in many alternate dimensions and that he was out to make sure that the Sersi of Earth-616 died. Proctor also reveals the existence of Ute. When his true intent to kill instead of rescue the Swordsman is revealed, Magdalene attacks Proctor. Later Black Knight plunges his energy sword into Proctor who then activates the self destruct sequence for his Citadel and disappears. Sloth and Cassandra are believed killed in the explosion, and Magdalene leaves with the Avengers in the aftermath.
In #372, Proctor returns with a a new team of Gatherers, including Rik, Sliver, Tarkas, Korg, and an alternate Jocasta. They attack Sersi and the Black Knight. Luckily, The Black Knight manages to disable some of them with a neural shock from his sword whilst Sersi battles back.
In response Rik blows up the port they were fighting on to prevent further losses on the Gatherers’ side but then Proctor teleports The Gatherers back to a rented townhouse in Greenwich village, telling them that he did not wish for Sersi to die yet – he wants her to suffer a little more.
In #375, Proctor and his Gatherers launch an all-out assault against the Avengers. The battle rages on, and the Black Knight, who has realised that Proctor is his parallel Earth counterpart, takes on Proctor one-on-one. The Avengers help him defeat Proctor and Sersi takes his life. Unable to overcome her madness, Sersi is forced to enter a dimensional rift into a pocket reality. However, the Black Knight decides to join her in her exile. Before dying, Ute restores all the damage that Sersi has done, including restoring the Avengers’ mansion.