Xavier is a man of action, he refuses to meditate or step back and consider things. He rushes headlong into situations and often finds himself in dire circumstances due to his poor philosophy. His cold demeanor leaves him with virtually no friends or allies, and he likes it that way. Other Jedi would immediately recognize how he walks a very fine line between light and dark.
Xavier Corwyn (9 BBY) was a average boy with some force potential until his life was forever changed by pirates who killed his family and scarred him. In his right palm is the image of a circle burned into his skin, it came from the muzzle of a blaster the pirate captain Froll who was responsible for the murder of Xavier's parents. He eventually found and killed Froll embracing the dark side in doing so. The essence of a powerful sith lord who was trapped inside a lightsaber inside a nearby sith temple on the planet where Xavier had killed Froll, lured Xavier in to it. The sith lord led Xavier to Dxun where he trained rigorously for two and a half years becoming a powerful dark Jedi.
By the time he had left Dxun the twenty four year old man looked like he was at least thirty. The dark side had already begun to corrupt him, along with the sith lord's influence Xavier's very soul was eroding away and being replaced by the sith lord himself. However Xavier would not go quietly into the night. The Sith Lord took him to a dream world where the two fought. Although Xavier almost paid the ultimate price he managed to kill the ancient sith.
He wasn't free yet however, the sith would attack him in his nightmares still trying to take his body over. Xavier saw only one solution to this, he had to find the Jedi. Maybe they could remove the sith lord's taint.
Xavier found the Jedi and a powerful Jedi Master, Kalja Sairu Leidias, removed the sith lord from Xavier's mind. Xavier felt indebted to the Jedi and decided to stay and help them build their academy. However he still was unsure if being a Jedi was the right choice for him. Faced with this indecision Xavier left the Jedi on Onderon in search for his own destiny. He could feel the darkness still inside him, the ancient sith lord was eradicated from his mind but he could feel his own spirit's desire for more power.
Xavier has an average aptitude for the force and is not a master duelist but his sheer tenacity and willpower is incredible. He employs unusual methods and whatever else he must use to accomplish a goal, collateral damage is most often a secondary concern.