He was the previous Dragonoid Emperor before Diga.
It's not known about the Dragonoid Emperor, but it could hint that unlike Diga, he cares about everyone in Sunh, and was not as power hungry as well.
Before the war began, The previous Emperor of the Dragonoid Emperor before Diga became the Emperor after the latter's unknown fate. It was peaceful at this time when he was still the Emperor. However, Dega, who was the general at the time, was able to defeat him and became the Emperor. It's unknown what happen to him, though it's likely that Diga killed him.