Rokai was a male Cardassian who lived in the 24th century. In the 2370s, he held the rank of dal in the Cardassian Guard. Sometime between 2328 and 2346, Rokai was Skrain Dukat's deputy at the Letau prison facility.
By the 2360s. Rokai had become the warden of Letau. In 2361, he worked with Dukat in imprisoning Iliana Ghemor there and kept her presence a secret. To prepare Ghemor for Dukat's arrival, Rokai would fill her cell with an anesthetic to incapicate her, allowing him to bathe her and inject her with a drug to make her cooperative when Dukat arrived.
In 2375, Rokai desperately attempted to muster his forces against escaped prisoners and invading Jem'Hadar after the prison was damaged by a crashing Romulan starship and Weyoun ordered the prison's inhabitants to be killed. Rokai was later taken prisoner by Ghemor and forced to help her, Shing-kur, Telal, Fellen Ni-Yaleii and Mazagalanthi to escape the prison. Rokai was killed by Ghemor after she learned her real identity. (DS9 novel: Fearful Symmetry)