To become one, a person has to be a Sith Warrior class and then choosing their advanced class at level 10 which can be done on the Imperial Fleet. You can then choose Sith Marauder from there.
the main sith lord in the old republic trailer is Darth Malgus
you can be jedi or sith
Darth Sidious, Darth Tyranus, and Asajj Ventress but you could argue that Asajj Ventress was not a Sith but an Assassin
to get a dual lightsaber/ double lightsaber on star wars you need to be a sith inquisitor or jedi consular and get one of these advanced classes Sith inquisitor= Sith assassin Jedi consular= Jedi shadow
Republic:- Jedi Knight Jedi Consular Smuggler Republic Trooper Empire:- Sith Warrior Sith Inquisitor Bounty Hunter Imperial Agent
Star Wars Knights of the Old Republic II - The Sith Lords - 2004 VG is rated/received certificates of: USA:T
If you mean how do you get into the Sith Enclave on Manaan then you have to go to the Republic Embassy and talk to Roland Wann, the leader. He will give you three options to choose from and all three will enable you to get into the Sith Enclave.
There is a sith in all of the star wars movies.
Play a Jedi or Sith class and finish the starting area quests.
I still can't beat him. Talk about a difficulty curve.
The Great Hyperspace War was a conflict between the Sith Empire and the Galactic Republic. It began when the Sith attempted to invade the Republic and expand their influence. The war culminated in a major battle on the planet of Coruscant, resulting in the defeat of the Sith Empire.