The loser and the unretrievable.
But Naruto can make it as simple as he pleases-anything to keep him going-and he can make it a standard case of search-and-retrieve. He doesn't even see it as saving Sasuke, really.
He just wants him back.
And then he sees him for himself.
And it is awful.
Because Sasuke looks at him and that dark something of Naruto's is flaring up again, because Sasuke is hurting him-it is painful, it is terrifying, and it is torture to see the eyes of someone you love and not see even a piece of yourself in them.
This is what happens.
It goes from Sasuke always saving him, to Sasuke killing him to Sasuke looking at him like he is nothing anymore.
And then leaving again.
And all Naruto can do is double over and sob, and lose himself even as Sakura tells him not to cry. Even as she cries herself.