The Void Stone, a meteorite from the same galaxy in otherspace where the Charon species originated, was a holy relic held by the Charon colony on Kayri III around the time of the Galactic Civil War. It had the power to dampen the Force powers of Force-sensitive individuals.
Sometime before 3 ABY, a Charon starship left otherspace and arrived in the Expansion Region of the galaxy. After the ship crash-landed on the inhospitable volcanic planet Kayri III, the survivors established a small colony with less than thirty-six warriors and bio-scientists. There, they hid themselves from the local civilizations, plotting to gain their own starship and continue the Charon crusade to eradicate all life.
At the center of the Charon colony was the Void Stone, a meteorite from otherspace which was taken from the heart of their vessel's wreckage. The Charon, as part of their death-worshipping religion, venerated this stone as a holy relic.
The Void Stone had an unusual connection with the Force. Any Force-sensitive person within one hundred meters of the Void Stone would have difficulty using their Force powers effectively. Even those who did not consciously use the Force would suffer from impaired connection to the Force. The hundred-meter range of the Void Stone's power covered the entire cave network of the Charon colony.