The kind of sad part here is that Duma actually used to be kind, believed in the power within a person, and wanted everyone to reach their maximum potential. Of course, he had a disagreement with his sister who believed in peace and wanted everyone to relax and indulge in pleasures.
Naga never actually fought the two, just forced them out for unrelated reasons. Duma and Mila refused to bind their power to Dragonstones, and so were in danger of their minds becoming degenerated. They were exiled to avoid fighting, Centuries passed with the two living their ideal worlds, until their eventual downfall.
The powerful yet honorable people of Rigel were soon twisted into heartless warmongerers, and the peaceful people of Zofia collapsed from within and their bountiful harvests were taken away.