For Dhaos have an evil medium deep type of voice, I know he's voiced by Patrick Seitz in Tales of Phantasia The Animation.

Character Description: Dhaos can come across as evil and megalomaniacal, but that is the result of his cold ruthlessness. He has his goals and would do anything to achieve them, with the ends justifying the means. At times, though, he can seem almost kind to the Great Tree Yggdrasill and Martel. In the past, before he was taken over by his anger and rage, he was a kind ruler who worried for his people, and he returns to this same personality after his death.