chilled monkey
Senior Member
First let's look at Lord Starkiller's depiction in the novel. While this is just a Force vision I think it's applicable since it's meant to be Galen seeing where the dark path will ultimately lead him.
Lord Starkiller is stated in the novel to be a master of Juyo. Accordingly his fighting style is fast and almost solely offense-focused to the point where he doesn't even bother dodging/blocking some blows and is willing to take light hits. However he's not a raging berzerker either. His attack is described as hiding "deadly subtleties beneath its wide swing" indicating a high level of finesse. He's also good at both integrating Force powers into his bladework and using his surroundings as a weapon, ripping planks from the walls and throwing them at his foe. He notes that even though the planks are deflected it still distracts his foe and takes energy away from his attacks, meaning he's a smart and observant fighter.
Next he sends lightning under his foe's guard. Although it is reflected, Lord Starkiller endures the pain and keeps amping it up until they're blown apart, showing high pain tolerance. Finally he uses the Force to haul himself up and Force grip his foe, lifting him into the air, before stabbing him to death.
In short, he is a fast and vicous offensive dervish but is also smart, tactical and skilful, with Force powers both strong and decently precise. As Jensaarai1 or EvanNova95 might put it, Lord Starkiller is not a tank come to crush you. He is a panther come to maul you.