Sasuke has a dream, one night, where the people in his life aren't people, but something… more. Demons and angels and gods, from all the religions he's stumbled across in his travels and more, and it's funny to see how the characters are cast.
Orochimaru's place is obvious, as the many-headed snake of Shinto lore. Sasuke doesn't quite remember what role Kabuto takes, but he's fairly certain it was something fitting.
Naruto plays the role of a sun god from some far-off country's mythology, someone who rides across the sky in a chariot that pulls the sun and makes prophecies when he touches down and walks among the people. Sasuke isn't sure what to make of that.
(Kakashi is an old man in drab grey clothing, hiding his power and seeking refuge from mortals. Sasuke's first instinct is to think it's a sign of his mooching, but it goes deeper when he ponders it. Everything was always a test with Kakashi, and he never showed his full power unless it was absolutely necessary, playing the weakling and the fool; the role of Odin is terrifyingly apt, in some ways.)
Itachi doesn't show up in the dream, which is both a frustration and a relief. Sasuke wants to know what his subconscious is telling him with the rest, whether it's obvious or not, but there's nothing to build on if the dream gives him nothing to consider.
The girls, though…
Sakura is an angel, all sweet light and kindness and waiting redemption if he would just take her hand.
Karin is a devil, and he'd laugh if it didn't make him want to cry that he automatically goes to her instead.
It's not that he hates goodness and light and whatnot. It's not that he thinks Karin is evil, or that he wants to cry because being with her is some kind of punishment.
It's because he knows, the second he wakes up, exactly why his dreamself runs to the fire and brimstone behind her, runs from Sakura's offers of painless wonder.
Karin isn't evil, or punishment. Karin is commiseration. Karin is shared pain, shared suffering, histories of horror that one cannot understand unless they too have lived through it. Karin, the real Karin, had lost her village, the only survivor by luck and skill; she was out of the village, running on instinct when she felt people coming by chakra sense. A Cassandra truth, he's heard it called. When Sasuke mentions his family, his brother, his lost clan, he sees pity or indifference from people, or maybe an attempt to sympathize that falls flat. With Karin, he feels a wince and a likes to imagine that he feels a soul-deep empathy, something that goes "you've lived through this hell, too."
Karin is the devil, not in that she represents a hell that is coming, but one that has already passed.
And, gods help him, he'll take a hellish understanding over heavenly ignorance any day.