What about in the crawl? Or does that say Dooku? I don't think he was mentioned as such in the beginning, cause the Jedi thought, "He's a political idealist, not a murderer."....."you know Count Dooku was once a Jedi, he couldn't assassinate anyone...its not in his character." So they didn't know in the beginning that he was a Sith. OB1 found out on Geonosis. And he still called him Dooku. Come to think of it, I don't think anyone but Sidious called him Tyrannus. And it was Lord at that.
Although he is never referred to as "Darth" Tyranus his Sith name is indeed, Darth Tyranus!
He wanted to keep that quiet, but someone forgot to tell Jango 😂
Anyway why would he call himself Tyranus when hiring Jango? unless Fett was in on the whole Sith returning thing!But then why would he tell Obi wan this?? 🤨