Contrary to popular misconception, blood is--for most people--a finite resource. That's quite often the problem, in fact. Many individuals have expired due to the finite nature of their blood supply. Johannes Cabal does not intend to be one of them. He's already anemic; he can feel the circulation a little duller in the tips of his fingers and toes, a little slower to burn if he holds them to a candleflame, and it only barely occurs to him that some might find this behavior of his a tad disturbing to witness. He's attached to his blood. He has good reason to keep an eye on how much of it he has. Even more reason than most.
So he waits until his newest wounds have scabbed over, a few days and bunches of spinach later, until Horst is cool and white and hungry again, before he summons his demon. It's not really
his demon, thank God, but it's easy to think of it that way: he's spent days picking it out, after all. He gets up a few hours before Horst in the late afternoon to sit and transcribe what he remembers of his spell oeuvre into a blank composition book. It's bleakly little. His memory is sturdy enough, no sturdier than that of any reasonably clever man with a disciplined mind, and the reason he keeps records in the first place is so he can rely on them--but he hasn't got his records any more than he's got his Webley, and so far no opportunity has presented itself to retrieve either.
Setting himself to the task of transcribing as many of his spells from memory as he can recall is his first silent concession to Taxon. It's a silent statement of,
fine. You've got me. I suppose I might be here a while. It's his first real admission that he probably isn't going to be strolling out of here tomorrow. But he really does have nothing better to do.
Besides, it's getting cold outside. Johannes turns on another electric lamp in the basement and holds his half-bag of blood up to the light, a cotton ball pressed into the pit of his elbow. It's just a lesser noble he's summoning, the magician's equivalent of a ping command to a command prompt, to see if he can still summon in this dimension. Wherever it is. Whatever it is. He doesn't quite expect it to work, but at this level there's only so catastrophically awry it can go either--
He drizzles his blood into a candle and paints the floor in meticulous brushwork with the remainder, a cheap horsehair brush from an art supply store taking the place of his usual hair-of-a-dead-child brush. It'll do in a pinch. Here, three of his hairs, there, ash from the fireplace--now, the demon's true name.
He's summoned it before. Irascible little blighter. It doesn't like him. No matter: he knows it, so he'll know if something's gone wrong. But there is something off about this place, he's fairly certain, so when Johannes mutters the last words of the spell and opens his eyes, he doesn't actually expect anything to happen: "By the authority of Lord Satan, the Adversary, the Morning Star, I, Johannes Cabal, bind you. I name you, Lord Paimon son of Orobas son of Amdusias. Obey me."
Life has a funny way of surprising him.