My apologies this is late @Alratan. I had to get access to my books.
Dead Beat
1)You have the trouble of unreliable narrator with Dresden, especially in the earlier books, where he, like the readers, is ignorant of much of the world.
For one thing, we know that his characterization of vampire magic is untrue for several reasons
-Thomas uses magic in Backup for a tracking spell. Entirely normal
-We see Bianca use magic in the denouement of Grave Peril. Different spells, no mention of a different source
-We see Ariana Ortega use magic in Changes in her duel with Dresden. She is described as having a shroud of greasy black magic around her, but her power source wasnt called out as any different.
And we see both Kumori and Cowl call on magic up close. There is no indication of their power sources being limited.
In conclusion? Magic is magic is magic. There is no evidence that Rampire or Whampire sorcerers are limited to a different source of power, let alone necromancers. Shit like blood sacrifices might be easier to do to raise power, like they did at Chitchen Itza in Changes, but it isnt necessary. Just a shortcut for people too lazy or too unskilled to do shit properly.
I cant speak for Outsider magic.
2) Also, Dresden knew nothing about Kemmlerite necromancy at this point.
He had to ask Bob for a briefing after Mavra told him to find the Word of Kemmler, because he didnt even know who Kemmler was.
And his briefing was incomplete because he tripped the Evil Bob switch and it nearly killed him, so he told Bob to lock away the info.
He only finds and memorizes the Word of Kemmler several hours after this conversation.
And when he reads it, he promptly raises Sue as a zombie tyrannosaur.
Using his normal power sources.
3)Word of Jim is that Odin uses soulfire to raise his undead Einherjar.
So yeah, necromancy.
Make of that what you will.
Fool Moon.
This is from even further back, when Harry was under the impression that a containment circle designed to hold a lou garou was rated to hold an archangel. And that demons were harmless denizens of the NeverNever to trade information with.
Fool Moon Harry was almost as dumb as he was ignorant.
And just to be clear: Harry does treat magic as his religion.
1)See my previous posts.
As of the beginning of Dead Beat, the only vampire sorceress he'd ever fought was Bianca, and he had only academic knowledge of necromancy. Dresden was a pretty inexperienced wizard at this point, with an incomplete education, as evidenced by the fact that IC he didnt recognize the name of the most infamous magical mass murderer in history.
Unreliable narrator tropes fully in effect.
2)He states no such thing to the Wardens. All that passage was internal narration.
I just went back and checked. Dead Beat chapter 31
That is all his internal narration, internal conjecture.Luccio nodded. "Precisely. The first attack came in Cairo, at our operations center there. Several Wardens were taken, including the senior commander of the region."
"Alive?" I asked.
She nodded. "Yes. Which was an unacceptable threat."
When vampires take you alive, it isn't so that they can treat you to ice cream. That was one of the really nightmarish facets of the war with the Red Court. If the enemy got you, they could do worse than kill you.
They could make you one of their own.
If they managed to turn a Warden, especially one of the senior commanders, it would give them access to a treasury of knowledge and secrets-to say nothing of the fact that they would effectively gain, in many ways, a wizard of their own. Vampires didn't use magic in the same way that mortal wizards did. They tapped into the same nauseating well of power that Kemmler and those like him used. But from what I understood of it, the skills carried over. A turned wizard would be a deadly threat to the Wardens, the Council, and mortals alike. We never talked about it, but there was a sort of silent understanding among wizards that we would never be taken alive. And an equally silent fear that we might be.
"You went after them," I guessed.
Luccio nodded. "A major assault. Madrid, Sao Paolo, Acapulco, Athens. We struck at enemy strongholds there to acquire intelligence to the whereabouts of the prisoners. Our people were being held in Belize." She waved a hand vaguely at Morgan.
"Our intelligence indicated the presence of the highest-ranking members of the Red Court, including the Red King himself. The Merlin and the rest of the Senior Council took the field with us," Morgan said quietly.
That made me raise my brows. The Merlin, the leader of the Senior Council, was as defensive-minded as it was possible to be. He'd guided the White Council into the equivalent of a cold war with the Red Court, with everyone moving carefully and unwilling to commit, in the hopes that it would give the war time to settle away into negotiations and some kind of diplomatic resolution. An offensive action like a full assault from the Senior Council, the seven oldest and strongest wizards on the planet, had been long overdue.
Not Warden statements.
3)Why would you believe anything Kumori said in the book without independent verification?
She's either the undead familiar or a magical associate of Cowl, attempted magical mass murderer . She was trying to recruit Dresden in that scene by convincing him necromancy wasnt so bad. She's not bound to tell the truth. Why would you believe anything she told you in a recruitment speech?
If she said the sky was blue, I would suggest checking to be sure.
Firstly, I'd ask for a citations that magic is magic is magic. Where is that said anywhere in the books?
Secondly, it'a specifically the Red Court that uses the same well of power as the Kemmlerites. What Thomas uses to cast spells is irrelevant, as he's a different order of being to different types of vampire. Also, I'm pretty sure there's a WoJ out there that Thomas does use a different power source, he uses his demon's Hunger.
In terms of why the use of another source of power isn't always called out, there's no need to. Harry's already knows it's different so wouldn't note it in his internal narrative, and OOC it's alread try called out so the author doesn't need to big the narrative down by repeating it. It may also simply not be that obvious.
And lastly, even if it was called out in the narrative, you'd probably deny it's relevance as being from the perspective of an unreliable narrator, just as you do Harry's direct observation of Kumori's necromantic signature.
Basically, it comes down to this, Harry may be a sometimes unreliable narrator, but his narration gives multiple examples of textual support for my position, including from when he has a lots of experience in facing both Necromancers and Red Court vampires and working with other people experienced in fighting them.
You, by contrast, have as as I can tell literally no textual support for your position, just your bare assertion.