In the late 2360s and early 2370s, she served as the first officer of the Denorios under the command of Captain Benjamin Sisko and became his confidant. By assessing the strength of his pagh, Opaka determined that he was the Emissary of the Prophets and attempted to convince him to accept his fate. However, Sisko refused to do so and ultimately forbade her from broaching the subject again.
In 2371, she was aboard the Denorios when it was attacked by the Klingon-Cardassian Alliance. Although she received only minor injuries, Sisko was mortally wounded and had died by the time that she had taken him back to Bajor.
By 2377, she was a member of the Bajoran dissident movement and an adherent of the underground Bajoran religion. At the time, she was, along with Jaro Essa and his wife Winn Adami, a member of the leadership triad of the dissident enclave in Vekobet in the Kendra Province of Bajor. The enclave was passed off as a labour camp in which the vital metal uridium was processed by slaves. In reality, the slaves, who were composed of Terrans as well as Bolians and Tellarites, were agents of the dissident movement, as were their supposed Bajoran masters. Vekobet boasted rich veins of uridium, meaning that the enclave regularly exceeded the Alliance quotas. The excess uridium was transported to their allies elsewhere on Bajor. Opaka posed as the camp's chief administer while Winn was one of her overseers. Jaro posed as the camp's physician and devoted much of his time to caring for Vaughn, who had then was a blind and extremely frail centenarian who was confined to a hospital bed. He was assisted in doing so by Vaughn's daughter Prynn Tenmei.
In January of that year, Vaughn's primary universe counterpart Commander Elias Vaughn and his superior officer Captain Kira Nerys made contact with the enclave and warned that the Iliana Ghemor of their universe was planning to discover the Bajoran wormhole and become the Emissary of the Prophets. Opaka showed the former Sisko's grave. Sisko's primary universe counterpart Captain Benjamin Sisko had previously led him to believe that the mirror Sisko was still alive and in hiding.
Shortly afterwards, Klingon forces from the IKS Negh'Var launched an attack on Vekobet. Recognizing that he would slow down Prynn and the other dissidents, he asked his counterpart to kill him. Commander Vaughn did so by shooting him with his phaser, which led to Prynn physically attacking him. While Jaro, Winn and Commander Vaughn were taken prisoner and transported to Terok Nor, which had recently been recaptured by the Alliance, Opaka and Prynn were able to escape through the Vekobet tunnels to another enclave.
After the Iliana Ghemor of the mirror universe became the Emissary of the Prophets, the Bajoran people converted to their long neglected religion en masse and the senior members of the underground religious movement came out of seclusion to reconstitute the Vedek Assembly for the first time in centuries. Several weeks later, Opaka was elected as the Kai of Bajor. With the destruction of the Bajoran Parliament in Ashalla and the consequent death of First Minister Li Nalas, the Vedek Assembly became the de facto government of Bajor with Kai Opaka as its leader. She used her new-found authority to have Bajor secede from the Alliance and turned over all of the dissident movement's stored munitions to the Terran Rebellion aboard Terok Nor. In response, Supreme Legate Skrain Dukat sent the Cardassian Ninth Order to destroy Terok Nor and conquer Bajor. Although Terok Nor was destroyed, the Ninth Order was defeated through the telepathic manipulation of the Vulcan slaves within the Cardassian Union.
In 2378, after the joint Terran Rebellion / Memory Omega fleet succeeded in stopping the Klingon renegade Krona from destroying Bajor's sun B'hava'el, Kai Opaka and Vedek Winn met with its leaders Miles "Smiley" O'Brien, Jean-Luc Picard and M'k'n'zy of Calhoun in the Elemspur Monastery in the Hedrikspool Province. (ST - Mirror Universe novel: Rise Like Lions)
|Kais of the Bajoran faith|
|Dava Nikende • Taluno • Shesa • Meressa • Arin • Opaka Sulan • Winn Adami • Pralon Onala • Kira Nerys • Opaka Sulan|
|Kais of the Bajoran faith in the mirror universe|
|Dava Nikende • Opaka Sulan|