Sarthisi

The ancient tongue of the Sarthi, said to hold power of life, death, and reality itself. The Sarthi used their magical speech to alter their enslaved peoples as they saw fit, and to reshape entire planets to serve their designs. It is assumed by many, though not known, that the Six Rings of Manan were forged by the magic of the Sarthi tongue: that the planets' resources were augmented and centralized in order to support their vast empire, whose power seemed to wane the farther one strayed from the six mighty star systems.
Today, only a tiny scattering of Sarthisi words are still known, and fewer still can be spoken by anyone living. The Sarthi were said to have three tongues, and that the few who could speak even a single word of their language were hunted down and delivered to mutilation and torment.