Egwene al'Vere, after receiving definite proof of the Black Ajah's existence in the form of member lists from Verin Mathwin's secret notes, returned to the Rebel Aes Sedai camp. After assembling the Rebel Hall of the Tower and swearing the three oaths on the Oath Rod and thereby proving herself not a Darkfriend, she proclaimed her knowledge of the Black Ajah's members, several of them found among the rebels. Among the Hall's present members, Moria Karentanis, a Sitter of the Blue Ajah, was discovered as Black, shielded and blocked, the same happening to Egwene's Keeper of the Chronicles, Sheriam Bayanar. The Hall then proceeded to forsake and reswear their oaths on the Oath Rod in turn, in order to prove themselves friends of the Light. Afterwards, they had all the Rebel Aes Sedai come by Ajah to repeat the process, resulting in over fifty Black sisters captured out of the estimated seventy that were in camp at the time.
Afterwards, back in the White Tower and in control of both factions as the true Amyrlin Seat, Egwene repeated the process within the Tower. But before the Purge started, the majority of Black sisters inside the Tower, around sixty, was alerted and able to flee - only a dozen of them were captured and executed.
All the Black Sisters outside the White Tower at the moment of reunification, especially the seventy among the unaligned sisters, were also able to escape the capture and join the Shadow during the Last Battle.
Somehow Mesaana was able to escape the reswearing process and she was not found. Because of this, Egwene gave Seaine, Yukiri and Doesine the task to theorize on methods to evade the power of the Oath Rod. But Egwene, due to Verin's warnings in the notebook, Sheriam's confession, and Egwene's own feelings, was aware of Mesaana's presence in the Tower. The young Amyrlin vowed to hunt her down, being able to defeat her just before the Last Battle.