Demmas

From Memory Alpha, the free Star Trek reference

Demmas was the heir-apparent and next in line to become the Autarch of Ilari. His father was killed by Tieran, a tyrant who could transport his mind into someone else's body. Demmas fled Ilari and enlisted the aid of the crew of the USS Voyager. He explained that Tieran had been overthrown by his family's ancestors over two hundred years prior, after which his family became the new imperial house and rulers of Ilari. He also informed the crew of Voyager about Tieran's ability to transfer his consciousness from one body to another, telling them that Kes, who had been taken over, was lost forever. He disagreed with Captain Janeway's decision to try and rescue Kes, and wanted her to use Voyager to destroy the pretender Tieran and his followers. Demmas and the Voyager crew were able to depose Tieran, and save Kes. Demmas, as the eldest son of the deceased monarch, then became the autarch. (VOY: "Warlord")

Demmas was played by Brad Greenquist in his first Star Trek role.