The Prince of the Underworld is the central character to the Dungeons stroyline. Originally he ruled the Underworld with sloth, as he sat on his Crystle Throne for long peroids of time doing nothing.
He dated the main antagonist, a succubus, for an unknown length of time before she stole his throne, breaking up with him moments before. Dispite this he has never shown any form of emotion, from the accusations of his minion Mr. Sidekick to his fall from power.
While never speaking directly he plays the commonly used silent persona. Dispite this his design leaves plenty of room for ideas on how he acts and what he is like.