Concentrated lightning attack

Vader threw wrecked platforms and cloning rubes at him, while he scored three slashes to the Dark Lord's cape in return. They circledthe top of the cloning tower, striking and assessing, then striking again. Starkiller swore that he would not give in to anger or frustration. If that was what Darth Vader wanted, he wasn't going to get it. The only emotion he would give in to was love.

The Force Unleashed 2, Chapter 23, Page 358