The Galra Empire once imprisoned him in a highly fortified installation known as Beta Traz, where he was subjected to torture to extract his knowledge for the Galra Empire. The Paladins of Voltron, Shiro, Lance and Pidge eventually staged a successful rescue attempt and helped him escape Beta Traz.
Slav was later called upon to build another gravity generator to conceal an enormous Teludav, intended for use against Zarkon's command ship.
Slav's main concern is his survival in any of the "alternate realities" that he believes and would do anything to make sure his chances are high. However, this contributes to him being fearful of just about everything from him possibly drowning from a puddle to breaking an alternate reality of his mother's back if he stepped on a crack. His cowardice and antics nearly puts his rescue mission in jeopardy and even riles up the normally cool-headed Shiro. However, he does have moments of courage when he opened the hangar doors to the Beta Traz so he and the Paladins could escape.
Slav is able to create highly-advanced technology like a space pocket dimension and a gravity generator to hide an enormous teludav. It's because of his genius however that the Galra imprisoned and tortured him in order to steal his technology for themselves.
- One of the writers, Mitch Iverson, stated that he based Slav off of Nikola Tesla, who was also a scientific genius and suffered from OCD.
- Another of his species was seen back in the first season, as one of the prisoners rescued during the mission to recover the Red Lion.