In the past Dongorio was good friends with the king of Regno, Io. Their plan was to invade the distant island that was inhabited by Beorns. The humans obviously had the upper hand, as the Beorns weren't prepared for anything. They would be shown mercy if they'd live under the reign of Dongorio, and so they did. Dongorio brought his son Mondo along with him to live there and later adopted an orphan Beorn, Unten. While his take over was hostile, his reign was peaceful. He however was thrown of his throne by Netnu during the Beorn Rebellion, which made him move to his new home in Occiden where Io made him the governor.
To the public Dongorio comes across as a light hearted and kind person, even when knowing of his hostile take over, they seem to respect him. He can be a quite strict man when he has to be, but does not display it much. While most people see him as a parental figure, especially with two sons, some things are quite different. He acts like a good father to Unten, while seemingly neglecting Mondo, and not accepting who Mondo really is. But these discussions are quickly thrown under the carpet, like they don't exist.
While nothing much is known about Dongorio's abilities, he does seem to have a good skill in leading people. But looking at his successful take over, it is speculated he used to be a great warrior.