darth atrius was an ancient dark lord of the sith who existed long before the rule of two was created. he owned two crossguard lightsabers, which were found and given away by the smuggler sana starros after the battle of yavin. the anger possessed by atrius when wielding both these crossguard lightsabers at the same time, carried over to the weapons themselves, and can transfer over to their new owners. these lightsabers were eventually destroyed by darth vader and luke skywalker, thus possibly erasing all knowledge about atrius himself.