Doctor Istan Zaly was a Separatist scientist and researcher. According to Adjutant General Wilhuff Tarkin, Zaly had remarkable success in analyzing the internal structure of kyber crystals using and building upon the original research done by the scientist Marsabi. He also formulated Zaly's theory, which hypothesized that a vast amount of power from kyber crystals can be stored in a physical space. Galen Erso refuted this idea in his discussion with Tarkin, calling it "flawed" and warning that there was no feasible way to contain so much power. During his work under the Separatists, Zaly created a weapon called the Zaly Shield. According to Doctor Chelli Lona Aphra, Zaly theorized that Kyber formed in opposition to Kyberite they were found in, which would make Kyberite useful for channeling and guiding the Force. This led to the Separatists believing they could amplify the limited Force potential an individual might have, convincing them to utilize the shield in that way. However, the Jedi who ended up battling those who utilized the shield simply used the shield's own ability against it. This combined with the shield's heavy nature made it particularly ineffective for battle. Therefore, the shield was eventually stored in Dr. Zaly's hidden headquarters in Ringo Vinda and put under secure guard. Zaly was at some point recruited by the Galactic Empire to take part in the design of the weapon of the Death Star, but later disappeared.