Possible Clues:

• Darth Vader's first name
• Obi-Wan's apprentice
• Luke Skywalker's dad
• A Skywalker
• Darth, before he turned to the Dark Side
• One of the Skywalkers
• Father of Luke and Leia
• Luke and Leia's father
• Luke Skywalker's father
• Darth Vader's given name