There are several fictional languages in the world of Beyond The Impossible. Most languages can be understood automatically by gods and have been completely translated by Noriko Null.
Modern Olympian (Ολγμπηαν): de facto official language of the Olympian Galaxy. Shown in the series as a translitteration of English with Greek letters, it doesn't actually share much with either modern or ancient Greek but has a similar sound.
Myridian (Μγρηδηαν): a regional dialect of Modern Olympian, spoken on planet Myridia. Mutually intelligible with Modern Olympian. Shown in the series as a translitteration of English with Greek letters.
Ancient Olympian (ΟΛΓΜΠΗΑΝ): the native language of Greek gods. Never shown in the series but sufficiently different from Modern Olympian to be unreadable by Myridians.
Demonic (دېمۆنلث): the native language of Demons, spoken on planet Hell. Cannot be understood by gods; Noriko Null and the Grey Lady are the only non-Demons known to have learned the language. Shown in the series as a translitteration of English with Arabic letters.
Grey Speech (■╪►◄ ‡•►►Ͻ□): the language spoken by the Grey Lady. Cannot be understood by gods; so far unintelligible by all other characters in the series. Apparently extremely alien-sounding.