Kohlen crystal shields represented a very specific kind of personal energy shield, engineered by the Pijali monarchy. A clandestine group of Pijali royal guards had been established as the blackguards by 40 BBY. This paramilitary group was under the direction of Fanry, the crown princess of an Inner Rim planet, and operated from a refurbished Celestial Watchtower base. The princess feared that Rael Averross, her Jedi lord regent, would try to stop her from becoming an absolute monarch on Pijal's throne. Therefore, Fanry oversaw the creation of shields utilizing kohlen crystals sourced from Pijal's moon, with the purpose of blocking Jedi lightsabers.
The novel Master & Apprentice, which was written by Claudia Gray and released in 2019, featured kohlen crystal shields.