- "There's only one academic who's written about the Rings. She's brilliant. A visionary. Even if the university doesn't think so. Doctor Eustacia Okka."
- ―Detta Yao
Eustacia Okka was a Mirialan female professor who worked for the Shadow University. She was once a classmate of the rogue archaeologist Chelli Aphra, but their relationship since turned sour. After she wrote an article on the Rings of Vaale, an artifact that was supposedly cursed, Okka was expelled by the University, who claimed she had insufficient credible research. Following her expulsion, she worked independently, assisted by the droid TA-418. During the Imperial Era, Okka was approached by a number of individuals searching for the Rings of Vaale, including Ronen Tagge, scion of the powerful Tagge family, and Aphra, who was hired by the student Detta Yao to find the artifact. Okka was initially hesitant, but eventually chose to help Aphra and her associates, hoping that finding the Rings would lead the Shadow University to reinstate her credentials.