4. Starkiller (Galen Marek)
Star Wars: The Force Unleashed managed to fill the gap in explaining what happened between Episodes III and IV. It followed Darth Vaders continued Jedi Purge and subsequent discovery of Galen Marek, better known as Starkiller, who became his secret apprentice, in defiance of the Rule of Two. Although Starkillers initial purpose was to kill any survivors of the Jedi Purge and Order 66, the subsequent betrayals by Darth Vader led him to become a principal actor in the creation of the Rebel Alliance. After his initial betrayal, Starkiller recruited many prominent opponents and critics of the Emperor to form a coalition of Rebels. In the first Force Unleashed game, the canonical ending saw Starkiller sacrifice himself to save the first rebel leaders from the Emperors hands. His sacrifice inspired them to formally create the Rebel Alliance, which of course set the stage for Episode IV. Whether or not Darth Vader and the Emperor couldve changed the Galaxy in the way they did without Starkiller is debatable. There is no way that Vader himself couldve sought out the Emperors enemies to create an organized Rebel Alliance. Starkillers destruction of the Empires assets and defeating of the Emperor were necessary in convincing people that the Empire was not all-powerful. Therefore, the central conflict in the original films could not have been possible without Starkiller.