Uthar is a true villain, not a pansy like Yuthura in any respect. Besides, he has a reasonable backstory, by which I mean one without all of the recycled "troubled past" nonsense that passes for Yuthura's character. In both villainy and general character, Uthar is standard; his apprentice is sub-par. Both are far outclassed by Jorak Uln, though, because craziness multiplies awesomeness.
"Grant Allen [...] had written a book about the Evolution of the Idea of God. [...] it would be much more interesting if God wrote a book about the evolution of the idea of Grant Allen." ~ G. K. Chesterton, The Everlasting Man