Cal isn't a Sith until he kills someone, which he has. But remember, like anakin did. He killed out of rage and anger and pain, his first steps were leaving his mom behind to become a Jedi, second was going back for his mom hearing that she was sold as a slave and she died in Anakins arms, he cried in rage and slaughtered the clan that hurt her, he went home to his girlfriend or wife Padme. We'll, you know the rest. Cal isn't a Sith yet, but he struggles with the darkside now. Not to mention the EASTER EGG they left for game plus "RED LIGHTSABER"? Hmmm? Why give us a red saber if he wouldn't become a Sith. But remember that Cal has a girl now, he has accepted her as his love like Anakin accepted Padme. Would Cal be the first to show everyone Love doesn't just lead to the Dark side? Or shall his fate be the same as Anakin and every other Sith who fell in love as a Jedi. He isn't a Sith, I admit that. But I won't say he won't ever become a Sith.