Yet LTW knows it when he sees it, which supports my theory that Martha Liberty (who has never seen Harry use it, due to Checkov’s broken leg) also has access to soulfire, he saw her use it in her role as a Voodoo Priestess. Eb, Christos and Carlos has seen him use it, unlikely that Carlos knew what it was especially as it was mixed with Winter power, and Christos is dead, so did Eb recognise it?
Most members of the White Council have little or no use for organised religion, so the chances of one getting granted Soulfire are slim, especially if a large number of them are jerks (though that didn’t stop Harry). Too many pursue power for powers sake, which disqualifies them, and they have to cross the Fallen, and most are too cowardly.
Vlad Dracul doesn’t seem a candidate for soulfire or being a wizard, and WOJ has it that he is something else forced into a human body. He was a member of the Order of the dragon, so could that be it? A Dragon or even a dragon forced into a human body and stuck that way? Drakul is Modern Romanian for Devil. Could Dracul have been a meat puppet for either Lucifer or another of the Fallen (not Denarians)
Wouldn't "modern Romanian" be post-Dracul/Dracula, and therefore influenced by the individuals? The origin for Dracul is Dragon, from the Order of the Dragon, which revolved around the story of St. George and the Dragon.
Real world-wise, there's not much reason for the order to have adopted the Dragon as its symbol, as the Dragon was killed by St. George after it demanded sacrifices. Interestingly, their symbol was the Dragon with its own tail wrapped around its neck, almost as if it were tamed by itself. Perhaps their symbolism was to turn that which had been evil to good?
Dresdenverse-wise, it'd be interesting if the Order of the Dragon was tied to doing just that. Imbuing someone with the power of the slain Dragon in order to let them wield it in a cause for good. Vlad II could have become their chosen host for the power, which is why he got the moniker. Maybe he was a Starborn and they thought he could control it, only things went... badly.