[Blut Vene. Sasuke watches, attention rapt with the sort of focus curiosity toward another's abilities tends to inspire in him — and someone as powerful as Ichigo seems to be especially so — falling quiet at that demonstration. A knife to skin, no injury. The shimmering color of blue is strangely beautiful; he can feel it, the echo of something like a fluctuation of energy that remains foreign all the way through.

Thoughtfully, Sasuke shakes his head.]

I wouldn't say the stone held any special meaning. It was black and veined with purple. The latter, I guess — it's the color that my chakra takes on when it becomes visible.

[And the black stone, perhaps because of his connection to darkness. How desperately he'd tried to live in it.]

Was it an innate ability, or were you taught? Blut Vene.