Summary: Darth Vader draws parallels.
Author's Note: This just sounded interesting; as you've probably gathered, I do a lot of my oneshots on whims. And if it looks like I treat Anakin and Vader as two different entities, it's because I do; the only thing they share in common is that they both see themselves as Luke's father and Obi-Wan as their old Master.
Disclaimer: I don't own Star Wars.
He can see Obi-Wan's mark on the boy immediately. Not in the way he wields his lightsaber, or the empty, meaningless words on his lips that were no doubt spoon-fed to him by the old man.
But by the look in his eyes.
Vader realizes that another ghost has found another way to haunt him and sing soft songs in what's left of his damaged, ruined ears when he sees all the light and the faith shining out of Luke Skywalker's bright blue eyes, so much so that Vader can barely see the resemblance Luke bears the man who was Anakin Skywalker.
Curse the old man for infecting him with the tired dogma of the Jedi. Curse you, Obi-Wan. You have infected my son with your old order's spirit.
Luke is the embodiment of faith, a trait that was first embodied (or at least it was supposed to be embodied) by the Jedi Order. In particular, a noted paragon of faith was none other than the old Master of Anakin Skywalker, Obi-Wan Kenobi.
Obi-Wan always showed faith in every circumstance, even when he spouted sarcasm and caustic wit at every possible moment. Showed the faith required in his own abilities to win battles, showed the faith in his clone soldiers that spurred them on to achieve great heights and victories.
Obi-Wan had faith in people. Namely, he had faith in Anakin. Even when he belittled and derided him, he still had faith in his Padawan to do right by him and others, to come out of battles unscathed, and when Anakin would be injured Obi-Wan only panicked for a moment before transferring his faith to the belief that Anakin would soon recover.
Obi-Wan had faith in the way the Universe worked, and that the Force would always lead him home.
And so does Luke.
He really is just like Obi-Wan. Kinder in his words, perhaps; less caustic, less prone to polite insults or sarcasm. But really, just like Obi-Wan.
All that faith shining out of his vivid eyes, and Vader can almost believe that it is Obi-Wan, young again but with fair hair, whom he's staring down as he raises a lightsaber.
Luke has faith in Vader. Faith that he will turn from the Dark Side, and return to being Anakin Skywalker.
And though Vader has cursed his old Master from the start from infecting his son with faith, now, he wonders if he shouldn't thank him, too.