AN: Shippuuden has really scared me. All of the characters are so awesome now, you're kind of afraid to take liberties with them...
But the whole Sasuke and Itachi bit is really cool, especially because *SPOILERSPOILERSPOILER* happens, and I've always wanted to do something with it. So enjoy.
Baku walk the night, meandering behind Itachi as if he were their pied piper.
The circles they walk in Sasuke's brain are inflamed and set paths; when he sleeps, he dreams of the dark places his brother has taken him, the lows of consciousness and valley bottoms of hatred; the deep, silent sea bottom with it's crushing pressures, the grateful fulfillment of discarding people and places in favor of a greater joy.
His deepest nightmares, the ones he wakes up unable to remember, are all the same; he's unoriginal, and that pains him occasionally. Itachi is all he thinks about, despises, and dreams of; there is no part of him that Itachi has not shaped into an avenger, and in his soul Sasuke hates him the most for that. No one takes him seriously, supports him with anything other than blind fancy; it's all his fault, itsallhisfaultitsallhisfault he sings himself into the dark with, knowing that the brother he hates and passionately pursues waits calmly behind his eyelids, ready to slay him in his sleep if he's not fast or strong or angry enough. It's hell, the torrid soup of Orochimaru's intentions and Itachi's quiet, unintelligible eyes churning between his ears. It's hell, hanging in the limbo and watching Itachi's little parade every night, marching gleefully through the firefly-stained nights Sasuke can barely remember. (Was life ever safe? Was it ever beautiful?)
Long-nosed demons and cats with glowing green eyes, formless things; shishiand jizo come to life from ages of beholding the futile passage of society, and all of them two-step in horrifying, happy slow motion behind the specter of his brother. Their hell-song melds with the gray as they follow a back that would, if Sasuke reached out and touched it, give way to the terrifying darkness of what's ladled over the apathetic night sky.
Itachi's neck twists, and his gaze snakes slowly over towards his brother, who is tensed with anticipation and sleepful paralysis; they're tiger eyes staring back at Sasuke, haunting and grasping and empty; in them Sasuke is small, the little wolf-son standing before the patriarch of the pack, determined and a little foolish, but mostly full of hatred.
They jump towards each other, claws extended and green eyes flashing like garnet chips- but Sasuke always wakes up before he can finally slay the tiger that birthed him.