Shadaric

When the Shadar-Kai first re-emerged from the Shadowfell they had lost the shared language of Taranic, and instead, they spoke a language unknown. A harsh yet vibrant language recognized only among their own. This harsh language seemed to inherently brim with arcane potential, resonating especially well with elemental and shape-changing magics.

Even the Guardian Dragons seemed to resonate with its elemental structure and understand it instinctively, which allowed them to plead their plight and return to the light of the Material. Since the Shadar-Kai would often keep to themselves, the language only really spread through arcane tradition.