Anakin
YOU WERE THE CHOSEN ONE! IT SAID YOU DESTROY THE SITH NOT JOIN THEM!
—Obi-Wan upset about his friend had turned into a sith lord
As a Jedi Knight and the prophesied Chosen One, it was said to be Anakin's destiny to destroy the Sith. Raised as a slave on Tatooine, Anakin became a jedi after being found by jedi master Qui-Gon Jinn. It was his early life, as well as the loss of both Qui-Gon and his mother that provided his original push towards a darker lifestyle. After having a dream in which his secret wife Padme died, Anakin finally fell to the dark side, due to his uncontrollable love for his wife.
Obi-Wan
Anakin's former master and a wise member of the Jedi high council, Obi-Wan Kenobi was an important general during the Clone Wars. He was, along with Anakin, onboard the Confederacy ship the Invisible Hand during the death of Count Dooku and rescue of Chancellor Palpatine (despite being unconscious for the end of the duel with Dooku). He was also responsible for the death of General Grievous, and was one of few Jedi to survive Order 66. He was eventually forced to confront his former Padawan in a battle that nearly resulted in Anakin's death.
Padme
Obi-Wan. There is good in him. I know it....
—Padme's last words
Padme Amidala, former queen of Naboo, is now the Naboo Senator of the Galactic Republic and secret wife of Anakin Skywalker. She dies due to her husband's rage, thinking she betrayed him to Obi-Wan, immediately after giving birth to twins, Luke and Leia.
Mace Windu
Jedi Master and member of the Jedi High Council, Mace Windu is considered to be the greatest living lightsaber combatist. He leads the mission to confront and arrest Palpatine/Sidious, where he is killed by Anakin, who is defending the "helpless" Sidious.
Yoda
The Grand master of the Jedi and leader of the Jedi High Council. Considered the oldest and wisest of the Jedi, Yoda is one of few masters to have survived Order 66. He eventually confronts Sidious in a lightsaber duel, but is forced to flee and hide on the planet Dagobah.
Mon Mothma
A girl who formed the Rebel Alliance to restore the republic.
Bail Organa
A guy who helped Obi-Wan from the Clones.
Palpatine/Sidious
Palpatine is the evil Sith Lord Darth Sidious, and the mastermind behind the Clone Wars, which turned out to be his scheme to turn the galactic Republic into the Galactic Empire. He was the master of Darth Maul and Count Dooku (Darth Tyrannus), and is now the master of Anakin (Darth Vader). He confronts Yoda in an epic showdown shortly after defeating Mace Windu and his team and not only executing Order 66 (having all jedi killed), but also declaring himself Emperor.
Dooku
Formerly a Jedi and Qui-Gon Jinn's master, Count Dooku of Serenno left the Jedi order after the death of his former apprentice. He later became a Sith Lord and leader of the Separatists. Under the guise of Tyrannus, Dooku was the one who provided the template for the clone army his jedi friend Sifo-Dyas had ordered. Dooku had previously confronted Anakin, Obi-Wan, and Yoda before on Geonosis, at which time he severed Anakin's right arm. He meets his death at the hands of Anakin Skywalker on the bridge of the Separatist flagship, the Invisible Hand.
Magna Guard
Carry electric weapons which can't be sliced by lightsabers and guard Grievous wherever he goes.
The Separatist Council
An evil council that teamed up to destroy the Republic and Nute Gunray is mostly the leader and wants revenge against Padme but all of them died due to Anakin.
Grievous
I am General Grievous! WARLORD OF KALEE! SUPREME COMMANDER OF THE DROID ARMIES AND I AM NOT A DROID!
—Grievous
A very formidable Robot that leads the entire CIS until his death. Steals lightsabers a lot often from every Jedi he killed. He believed to be a guy named Sheelal once and hated the Jedi for no reason. He can carry 4 lightsabers at the same time and fight with 4 lightsabers at the same time during combat.