Naruto is alive.
That's all he can think of right now, perched on a tree branch, high above the ground, high enough that a fall would kill him. If he was so inclined to fall.
He's tired of falling.
Naruto is alive.
The price he was supposed to pay for the power that would remove the pain. Why hadn't he? Why…? If you want something bad enough, it means it's important enough to have to sacrifice a few things along the way. All he'd had to do was finish Naruto off. He'd been unconscious and without any chakra left and so utterly defenceless that Sasuke could have killed him with a rock.
"When I'm with you… I think… maybe that's what it feels like… to have a brother."
Sure it is, Naruto. Brothers try to kill each other all the time. And he's not being sarcastic, either.
He doesn't understand why Naruto loves him. Because Naruto does, and Sasuke can't admit that without it causing him pain that he's used to. If they're like brothers… if they're… Sasuke hates Itachi. Sasuke hates himself.
He can't hate Naruto. But then, that's the point, isn't it?
Why don't you hate me?
He wonders if Itachi hates him. Wouldn't that be cute? He wonders if he's the vertex of this whole thing, in the middle, both the hater and the hatee. The victim and the perpetrator, the innocent and the horrifically guilty.
Except Naruto doesn't hate him, and in both cases, Sasuke is still the loser. Second best to Itachi and one worse than Dead-Last.
Itachi is evil. Naruto is good. Sasuke is somewhere in the middle, but not of his own doing, his fall instigated by Itachi and arrested by Naruto and now he's not sure where to go.
But wherever he goes, Itachi's murder will somehow be involved.
He doesn't know where the power will come from, or if he even will be able to find it on his own. He doesn't know how far he'll have to wander, or how many people he'll have to fight, or how many times he'll have to think he's going to die.
One day, he'll realize that the only path to murder has murder along the way. Perhaps he won't still be searching, hungry, desperate, by that day. But if it comes to that…
He can always pay the price later. After all, brothers kill each other all the time.