This would have to be Darth Sideous, Palpatine, the Emperor himself. It is clear that Dooku is playing him like a fiddle. I see no fear in him which leads to hate and anger leads to the dark side. He wants power, since he already has the title of Count because of the riches he has aquired, now he wants more, knowing what Darth Sideous has planned in the future. Dooku already said he has become more powerful than any Jedi. I'm sure he thinks he is invincable to anything that gets in his way. Why did he tell Obi-Wan to join him & together they can take out the Sith. Also he revealed that a sith by the name of Sideous is in control of the senate. He is planning something behind Sideous' back but I'm sure that Sideous already knows.