--Even in my world alone, people tell the story in different ways, with different explanations. And I've seen two very different versions of the same person come here.
So I thought... Perhaps, if the Cain of Castiel's world killed Abel for a different reason, the punishment might have been different.
[it sounds as if he's trying to indirectly ask about it, but he doesn't care about that. he meets Naoya's gaze again and says, soft] But making the punishment fit the crime -- obviously doesn't fully apply. [because he knows Naoya couldn't have deserved this punishment; not when he loves his brother so much. and he can't imagine any crime that would merit a punishment like this]