Quote Originally Posted by Catullus64 View Post
I see the use of condemned criminals as sacrificial victims pop up a lot in fiction, and it seldom reads right to me. It seems kind of like tossing the gods your leftovers, and I would think that any god important enough to receive state cult would be offended. You wouldn't dare offer the god a sickly and starving bull, why offer a morally degenerate person? If the god's not picky, why would you honor criminals by making them into divine offerings? I suppose the idea could be that it's not an offering, but a punishment for the criminal's offense against the divine, in order to exculpate the community; but in that case I don't think would be proper to call that a sacrifice.
I see your point, but in this case it's less about sacrificing people to the gods and more about needing their blood to fuel magic (including the magic that keeps the city safe) so I don't think it would apply in this case (though I could see someone spinning it in-universe as sacrificing to the gods, I might use that). There's also people giving away or selling some of their blood while still alive (sort of like real world blood donors) but the idea is that killing someone gives the blood more power (and, of course, provides more blood).