The plot from the Force Unleashed from Wookieepedia
http://starwars.wikia.com/wiki/Star_War ... _Unleashed
The Force Unleashed features a young man by the name of Galen Marek (codenamed "Starkiller"), the secret Sith apprentice of Darth Vader, and his missions as such in the year 2 BBY. In the first level of the game, you take the role of Darth Vader on Kashyyyk in search of a new apprentice. At the end of the level, Vader finds a young Starkiller, choosing him as his apprentice. Marek is dispatched by Vader to eliminate several Jedi who survived Order 66. His first target is Rahm Kota, who used militia instead of clones and thus survived Order 66. Starkiller sets out with his pilot Juno Eclipse and droid Proxy in order to track Kota down. After defeating both militia and stormtroopers alike, Starkiller finds the general, and defeats him in a fierce saber duel. However, during the duel, Kota predicts that Vader won't always be Starkiller's master, and that someday Kota will be instead. Starkiller casts Kota out of a burning space station re-entering a planet after blinding him. Not altogether sure that Kota is dead, he steals Kota's lightsaber and leaves. His loyalties are tested, and he eventually turns against Vader. Marek helps form the Alliance to Restore the Republic, and then sacrifices himself in battle with Vader and Galactic Emperor Palpatine to allow his new friends and Rebel leaders to escape.
Galen Marek (Starkiller) biography:
http://starwars.wikia.com/wiki/Galen_Marek
With the Force as his ally he did battle with the Dark Lord. And he showed the measure of a true Jedi at a place called "The Death Star" where hope for the Galaxy was reborn. May all who struggle against tyranny hold his memory in their hearts