Zaria, from Ultima Underworld II
Zaria is a sorceress in the Pits of Carnage with a very high opinion of herself.
When talking to Krilner and Zogith in Ultima Underworld II, the Avatar learned that Zaria was second only to Dorstag in the pits. Since Dorstag denied the Avatar a duel for the Blackrock Gem, feeling the Avatar unworthy, a duel with Zaria seemed the logical choice to gain his respect.
Talking with her, it quickly became clear that she had a very high opinion of herself, and she seemed certain that she would defeat Dorstag in the future. She also tried to lure the Avatar into a duel so that she could chose the Arena of Air which was to her advantage. However, the Avatar had the option to imply that a woman couldn't fight anyway, a little odd when the Avatar is female, which enraged Zaria so much that she demanded a duel, giving the choice of arena to the Avatar.
In the following duel, she perished, and Dorstag felt that the Avatar was worthy of dueling him.
It is also possible to let Zaria live by defeating Dorstag earlier. After that, Zaria is willing to challenge Avatar for the title of number one. However, the Avatar can decline, telling her she's free to rule while the hero is absent. Zaria happily accepts.