Tyball

Tyball is a mighty wizard and the main villain in Ultima Underworld I.

Tyball and his brother Garamon were mighty wizards, so powerful that they lived in the extremely dangerous 7th and 8th level of the failed colony in the Abyss. One day, they did a mistake and accidentally summoned the Slasher of Veils. While they tried to find a way to ban him, Tyball was seduced by the daemon and killed his brother in cold blood. After that, he erected a terror regime in the 7th level of the Abyss, absorbing all magic in the area.

But the Chamber of Virtues, where the Slasher was held, was locked, and Tyball looked for ways to open it. Finally he found it: He had to sacrifice a virtuous virgin person after a long ritual. So he abducted Arial, daughter of Baron Almric, who fit these criteria perfectly. This however, set the Avatar on his trail, who was accused of the crime. In the end, the Avatar found Tyball and killed him, before the sacrifice could be done.

Trivia

 * Funny enough, his portrait and the way he looks in the cutscene look nothing alike. The cutscene-look is the canon one, as it is more detailled and was also used in the cluebook.