Asag is spoken of frequently in Gialon texts as the 'serpent betrayer' that would join them in battle and made home for centuries at the sumit of Nasudana's steep mountains far above the Temple of Syfyr. Interestingly, Asag is also mentioned in Half Dragon texts as being the destroyer of Python.
From rudimentary art found of the dragon it appears this dragon was either diseased or cursed or possibly a poison elemental dragon.
Connecting the dots, some scholars believe that Asag was once banished from the western continents by the dragons and made his new home in the land of Nasudana. Whether or not he returned to save his homeland during the attacks by Python is unknown as it is difficult to place these events chronologically. He was either banished before Python or after