Detta bekräftas under Star Wars: Episode II: Attack of the Clones ...
När Obi-Wan konfronterar Jango Fett:
OBI-WAN: Sifo-Dyas. Isn’t he the Jedi who hired you for this job?
JANGO: Never heard of him. I was recuited by a man called Darth Tyranus on one of the moons of Bogden.
Och i slutet av filmen:
Count Dooku: The force is with us, Master Sidious.
Darth Sidious: Welcome home Lord Tyranus. You have done well.
Yoda bekräftar att med ett prefix av Darth, som gör honom till en Sith:
OBI-WAN: One more thing. Jango mentioned he was recruited by someone named Darth Tyranus. Any idea who that might be?
YODA: With the forename Darth, a Sith he must be.
Citat kommer från imsdb .