Following her reappearance, the Knight of Hell started gathering forces to take control of Hell from Crowley. With the help of Jason, Abaddon gathered a small group of loyalists and battled a group of hunters, including the Winchesters, in an attempt to get Crowley's location. However, the angel Gadreel revealed himself and killed Abaddon's demons, causing her to retreat.
Despite her defeat, Abaddon was able to continue gathering forces loyal to her in her efforts to take over Hell. The demon Cecily stated at one point that Abaddon has "a few of the more aggro types on her side, but most are waiting to see who wins the belt: you or her." After learning of Crowley's location from Cecily, Abaddon and two of her loyalists cornered him in a warehouse where Crowley had helped to expel Gadreel from Sam Winchester. However, the two demons refused Abaddon's order to kill Crowley and witnessed the exchange between the two where Crowley promised to work to win the hearts and minds of regular demons to defeat Abaddon's coup.
While following Crowley, the Bar Demon tracked him and Dean Winchester to the house of Cain. The demon summoned an army of Abaddon's loyalists to attack Dean, Crowley and Cain. After a brief skirmish between Dean and a few of Abaddon's followers, Cain gave Dean the Mark of Cain and the location of the First Blade so that Dean could kill Abaddon. Cain then proceeded to single-handedly take on and kill all of the Abaddon loyalists that had shown up at his house. However, this fight drove Cain back under the influence of the Mark of Cain and back to killing again.
Abaddon managed to implant a spy close to Crowley in the form of a demon named Lola. From Lola through another loyalist named Aldo, Abaddon learned of Crowley and the Winchesters search for the First Blade. Crowley killed Lola after discovering her deception and Abaddon's loyalists began their own search for the legendary weapon, but were unable to find it. After killing Magnus with the First Blade, the Winchesters and Crowley discovered that Abaddon's loyalists had searched the Impala for the weapon and scratched an Enochian warning to Crowley into the side of the car.
Shortly after this, Sam investigated an apparent case of demonic possession and discovered that two demons loyal to Abaddon were stealing souls for her that Abaddon could shape the souls into an army of demons loyal only to her. This was a plan at least partially embarked upon by Abaddon in 1958. Though Sam killed the two demons and returned the souls to their rightful owners, he learned that there were other such factories all over the place. Other hunters reported seeing similar factories run by Abaddon's demons shortly after this discovery.
A few months after the discovery of Abaddon's soul-stealing plan, her army of loyalists had grown vastly and included some of Crowley's trusted advisors. With their help, Abaddon lured Crowley into a trap at the Humboldt Hotel using his son. In the battle that followed, Dean managed to kill an Abaddon loyalist and Abaddon herself with the First Blade.
Following the death of Abaddon, the organization disbanded and her followers returned to Crowley's side, restoring Crowley to rule of Hell. However, some of her followers were not happy with Abaddon's death. The demon possessing Drew Neely and another loyalist attempted to kill Dean Winchester in revenge, but Dean was now a Knight of Hell himself and easily killed the two demons. It was discovered by Sam Winchester that Crowley had "fed" these Abaddon loyalists to Dean in order to feed the Mark of Cain.
After regaining full control of Hell, Crowley began punishing those who had acted against him, particularly Abaddon loyalists. He had at least one demon executed with an angel blade for his acts of collusion with Abaddon.
- Abaddon (leader, deceased)
- Jason (deceased)
- Bar Demon (deceased)
- Muffin's Owner (unknown)
- Abaddon's Henchmen (unknown)
- Abaddon's Demon Army (deceased)
- Aldo (unknown)
- Lola (deceased)
- Sister Agnes (deceased)
- Mr. Richie's demon (deceased)
- Crowley's Trusted Advisors (defectors, unknown)
- Humboldt Hotel Guard (deceased)
- Abaddon Loyalist (deceased)
- Drew Neely demon (deceased)
- Executed Demon (deceased)
- Many unnamed demons