We've all observed that the White Council is freaked out because Harry is accumulating power and connections at a tremendous rate, and starting to remind them of Kemmler. But it occurs to me to wonder, purely speculatively (it has to be speculative since we have little data), if there are more parallels than we know.
Bob informed Harry and us that Kemmler was one of the causes of World War I (I'm sure he was not the sole cause, there were a lot of quite mundane reasons why a big European war was likely in the early 20C, but we know from Bob that Kemmler played a big role building that up ver the previous century, too). Bob told us that Kemmler had connections with the major vampire courts, the nastier Fae, and so on.
It occurs to me that no matter how brilliant and naturally magically strong Kemmler was, building up all that would take a long time. Kemmler might have been a major innovator in necromancy, but I'm sure he didn't come up with his knowledge overnight.
Why did it get so far? Why was in only in freaking 1961 that the Council finally punched Kemmler's ticket, after all that? World War I ran from 1914 to 1918/19 (depending on when you count it ending) and its aftereffects went on for decades. Necromancy is a straight Law violation in itself.
What I'm getting at here is to ask, given the Council's chop-happy approach to the Laws, how is it that Kemmler wasn't neutralized fairly early, while it would still have been relatively easy?
My speculation is that the Council wasn't always as chop-happy as Harry has known them. Any human organization, over generations, goes through phases and changes, things get stricter or easier, attitudes get softer or harder. Wizard lifespans would make the Council slower to change, but it's over 2000 years old, so it's certain to have gone through such phases.
My speculation is that in the late 1700s/early 1800s, maybe all the way up to the turn of the 20C, the Council was a lot more easy-going. I'm sure they still executed warlocks and enforced the Laws, but they might well have been more willing to see grey areas or grant second chances, too. I wonder if it was in a 'more relaxed' phase.
Which might have enabled an up and coming young warlock to grow into Kemmler himself. There might have been doubts about his intentions. Maybe he hid the bad well, or maybe his first indulgences in necromancy were technically legal, like Harry and Sue. Maybe he even did some good stuff, so the Council wasn't sure about him, and they erred on the side of mercy.
And the result was World War I (and as a side-effect of that, the USSR, World War II, the Holocaust, the Cold War, etc. All that stuff flowed from World War I one way or another.) and a near-miss elevation of Kemmler to Mab-level power in a darkhallow.
OK, the Council finally caught up with Kemmler and put him down in 1961. Harry killed Justin sometime around 1988-1992. (If Harry is born in the early 70s, that makes him 16 around then.)
If my speculation is right, post-Kemmler the Council is probably traumatized and maybe guilt-stricken over the scale of the deaths and suffering and horror Kemmler caused, and determined 'never again'.
If we count in everyone that the USSR either starved intentionally in the 1930s or mass-murdered in the gulags, and everyone the Nazis murdered, plus the deaths of soldiers and civilians in the World Wars, plus the maimed, the blinded, the mentally broken, then Kemmler's direct and indirect butcher's bill is in the hundreds of millions.
Then on top of that, Kemmler is narrowlly stopped from becoming a small-g god in a Darkhallow.
So it would be completely understandable if the post-1961 Council took the attitude that public safety now takes absolute precedence over justice or mercy, with no meaningful gray areas. So the post-1961 Council is chop-happy, they no longer err on the side of letting the innocent slide, they're more concerned with making sure no more mega-warlocks get past them.
(If I'm right, eventually that phase too would pass and things would relax somewhat again, but given Wizard lifetimes that might take a century or more.)
This theory might explain Maggie Sr. too. Apparently Margaret had been a thorn in the Council's side for a very long time, but she still lived. But if my theory is right, after Kemmler went down the Council was no longer prepared to tolerate such thorns, and the orders went out to the Wardens to hunt her down and kill her. Lord Raith beat them to it, but we have it straight from Ebenezar that the Wardens were hunting her, not just watching.
It might be that the late 50s/early 60s war with Kemmler caused the Council to say, "Enough of this crap!" and start cracking down hard on warlocks and proto-warlocks and anyone who looks like they might become a warlock.
