"I could buy a slaughterhouse and launder the blood through that? Or try figuring out a permanently refreshable blood set-up. Assuming that millieays doesn't have access to some sort of bulk waste disposal service?" That last bit is directed at the Bar.

Not exactly; things tend to get out of the way over time but not to the point where it would be convenient to have blood flowing through the halls. Let alone into the lake; there's a giant squid living there and he might object.

"Is running a pipe out through the front door doable?"

The door generally needs to be held by a person.

"We could open it and let the excess blood drain out once it's no longer usable, and then close it? Plausibly every hundred rituals or so if we can get the right sort of tentacle."

"What exactly is the function of these tentacles?"

"Refreshing the blood so it can be used multiple times."

"...right, but, what is the property of the blood that the tentacle alters and how does a tentacle do that."

"Uh, I might be bad at explaining this - I havn't really had the chance to talk about the details of the ritual with anyone I trusted with it before."

Lucien collects his thoughts.

"So the original resurrection spells requires each sacrifice contribute three times the amount of blood in a human body, typically meaning you had to bleed them several times and wait months for their blood to regenerate in-between bleedings. But there was a note in one of the versions of the rituals that indicated you could substitute in the blood of enough relatives of the sacrifice, with more blood the more distant the relative, and I eventually figured out that with a really really large amount of animal blood you could get it to work. But the fact that it's not their blood produces some byproducts - I'm not really sure what - that degrade the efficiency really badly after each use requiring even more blood. So I have a different spell that allows tentacles to sort of consume and excrete blood that turns out to work as a filter for removing the byproducts. Mostly filter - it still fails after enough uses."

"...so, how much will you need if it is their blood?"

Lucien does some mental arithmetic.

"4 gallons for each person you are sacrificing?"

"That amount we can just, like, dump in the toilets in the bathroom or something, with a few live-enough-to-walk-around Elves helping."

"Where would we get the blood?"

"...me?"

"You can create blood? Of an arbitrary person?"

"Yes. I mean, in terms of physical composition, if it's relying on having once been in their body we have more of an issue."

"It's not - otherwise the tentacles wouldn't work. Your magic is very impressive."

"Thanks."

"Hrm, I think that arbitrary blood would allow a lot of very terrible curses to become much easier to arrange so this is another reason to be careful about introducing demons to my world. But possibly there is a solution to this."

"...a solution to demons being able to make arbitrary blood, or a solution to arbitrary blood being usable in curses?"

"Either? Or a way to enable demons to do resurrections to without risking people finding out about the other things they can do."

"Well, that requires cooperative demons, but I can do some vetting of individual ones if you don't want too many, we can correspond before summoning."

"Seems reasonable."

Lucien can provide Cam and bar with furth details about the resurrection facility they'll be building - it really doesn't have to be nearly as large now that they won't have so much blood.

And this is all in Milliways and Cam doesn't have to leave it, right?

Assuming Milliways is fine with this, yep.