Well this is a really out there WAG, so bear with.
I think there is a possibility that Harry is either one or both of the following:
1.The Original Merlin, the one who founded the White Council.
2. THE Anti-Christ, as in the bringer of the apocalypse, but not necessarily the "son" of the Devil.
Allow me to explain. Jim mentions in an old WOJ about the origins of his Vampire research a man called Montague Summers. Montague Summers was a somewhat mad (or at least very weird) writer, who wrote about Vampires, Werewolves and Witches etc in 1928 from an academic point of view. Not the myth, per se, but what he seemed to believe were real phenomena. Jim seems to be quite the fan; indeed much of the Dresden Files contains similar philosophy and exposition on the creatures and spirits that are showcased.
For instance, Summers describes a Vampire in it's most basic form as a living dead body that drains the life and destroys a victim. This is very in-keeping with the Black Court. The Stoker-traits were a relatively new thing, and the various Hollywood movies that helped create the image of the modern set of vampires. He has also said that he based the White Court on a mix of the old incubus/succubus mythology and the sort of twilight-esque "hearthrob yet wildly misunderstood" vampire type that emerged recently. Interestingly, Iago (Fred) who used to play AmberMUSH with Jim said that the White Court were very similar to a type of chaotic-house characters that he and Jim created for campaigns. Finally, the Red Court and Jade Court seemed to be rather similar to the cultural lore of their locations in the books (Mexico and surrounds, and China respectively). But I digress.
He also has similar rules to Summers' in the early books - only beings of the flesh can affect the material world, ghosts are spirits and cannot generally affect the material world (without breaking things basically, including themselves) and Angels and Demons seem to have a bit of both, although particularly he mentions the idea that Demons can generate or possess a body, but it is not their "true" body. Their essence.
Anyway, Summers' mentions the idea that a Vampire occasionally was thought of as the offspring of the Witch and the Devil. He also references the thought that the Antichrist will be born through the carnal interactions between a human and a demon.
Merlin was oft thought to be the child of a witch and a Incubus. He also was occasionally thought to be the Antichrist.
Finally, I quote this "the children thus begotten by Incubi are tall, very hardy and bloodily bold, arrogant beyond words, and desperately wicked".
If that doesn't sound like Harry Blackstone Copperfield Dresden, I'll eat my shoe. The "desperately wicked" of course, is debatable and depends on your POV and beliefs. But the rest is him to a T.
But how do we solve the fact that the Original Merlin was running around at the very least 1500 odd year before the events of the series, and that Harry clearly isn't him (currently)? How also do we solve the fact that whilst Harry's mother was indeed a witch, his father was (as far as we know) a vanilla mortal?
Well Time-Travel magic would solve the first problem, easily enough. If Lord Raith was Harry's father though, wouldn't he have been like Thomas? Surely come 18 wouldn't he have become a WCV or at least had the pull of it?
My guess is that it could be one or two things. Perhaps Harry's "real" father wasn't Lord Raith, but an Outsider or even the Devil. And Malcolm was to Harry what Joseph was to Jesus, the Christ. We know Harry's birth on Halloween in-part had something to do with being a Starborn (and probably, a Destroyer). We know that Halloween is the time when the walls between the spirit world and mortal world are thinnest, and all immortals are mortal whilst they are upon the mortal Earth. Perhaps it is more than the conjunctions, perhaps there is something else.
Thoughts?
