Count Dooku, also known as the Iron Duke, is an effective troller who works for Darth Sidious. He is a master swordsman and he looks a bit like Saruman. This is because they are actually brothers, which explains why they are so powerful.
He also hates Anakin Skywalker, aka Darth Vader. This is because he has a hunch his master will want to replace him soon, so he makes his own Darth name: Darth Tyranus.
Tyranus decided to hunt down Jedi and made a fierce enemy of Macey Space, which wasn't a good idea. However, it turned out that the two were completely evenly matched so they decided to go their seperate ways.