Dooku, a Force-sensitive human male, was a Sith Lord who led the Confederacy of Independent Systems as Head of State during the Clone Wars. Although he was once a Jedi Master, Dooku left the Jedi Order and the Galactic Republic after growing disillusioned with the corruption in the government. Turning from the lighthe once served as a Jedi, Dooku joined the dark side of the Force and became the apprentice of Darth Sidious, the Dark Lord of the Sith, taking on the name Darth Tyranus and reclaiming his title as the Count of Serenno. With his master, who was secretly Supreme Chancellor Sheev Palpatine, Dooku conspired to overthrow both the Republic and the Jedi so that the Sith could reclaim their former dominance. To this end, he oversaw a growing secessionist movement that ultimately resulted in the formation of the Confederacy of Independent Systems. In addition to rallying rebellious star systems to the Separatist cause, Dooku was involved in the creation of the clone troopers of the Grand Army of the Republic, having supplied the Kaminoans with the clone template, Jango Fett, as well as the inhibitor chipcontaining Clone Protocol 66. As a result of Dooku and Sidious's machinations, the galaxy became engulfed by the Clone Wars twenty-two years before the Battle of Yavin.

This voice is a big part of the series, and this needs to sound very close to Corey Burton's Dooku from "Star Wars: The Clone Wars".

Example: https://youtu.be/Ntb8kpgW_n8