It likely didn't have any to do with the healing spell that Kratos that had just performed, but slowly the darkness started to peel away from Sora's skin, flaking off and disappearing into thin air as he slowly reverted back to his own form.

His claws became fingers again. His eyes, while closed, were no longer yellow. His clothing was splashed with color once more, until he finally looked like a boy again.

But what had also stayed was the wound in his chest and his back, and the blood that now stained his body. His chest didn't move. His fingers didn't twitch. He was completely still, draped partly over Tsurugi. There was no way for the two to ignore what had happened, even if it had been necessary. And if he looked slightly peaceful even in lifelessness, maybe that was for the best.