Eredun
The original language known as Eredun was spoken by the uncorrupted Eredun of the planet, Argus. After the majority of the population joined the Legion, the original tongue saw a divergent evolution. The Eredar of the Legion saw their language become the root of a conglomerate language adopted by all demons of the legion; a combination of the original eredun, in addition to the other tongues spoken by the demonic races of the legion, as well as some words of the titanic language of creation.