Ant, what's with your hatred towards Dooku? You seem to really dislike him.
@Jmanghan - Adas was the big boss before them, sure, but Ragnos is canonically more powerful than him and later Sorcerers probably uncovered more about the dark side than he was able to. Of course, it's just as possible that knowledge from Adas' time was lost over the millennia, but I personally believe that later Dark Lords were both naturally more powerful and had the benefit of greater knowledge and studies in the dark side.