Soulcalibur IV is a fighting game by Namco. This installment is unique to the series, as Namco and LucasArts came to an agreement to include Darth Vader (exclusive to PlayStation 3) and Yoda (Xbox 360) as playable fighters. Galen Marek, the secret apprentice of Darth Vader from The Force Unleashed, was also made an unlockable character under the name "The Apprentice" in both console versions; however, his endings are different in the two versions; the PS3 version is longer and features Darth Vader.
On October 23rd, 2008 Yoda and Vader were both made downloadable content for the systems they were not natively on. Vader costing 400 MS points and Yoda costing $4.99. These changes allowed Vader to be in the second to last battle of Yoda's story mode, and Yoda in Vader's. It also extended the ending of The Apprentice's story mode on the 360 version to that of the PS3 version.
An Infinities comic titled Star Wars: Visions of the Blade was later published on StarWars.com to provide a possible explanation as to how Darth Vader, Yoda, and The Apprentice (named Starkiller in the comic) ended up in the Soulcalibur IV universe.