I haven't quite thought out all the implications, but here goes:
When Harry meets with Lily under the truce, she implies that Nemesis corrupted Denton and his fellow FBI agents and that is what caused them to go power mad. This bothers me, because someone still had to physically make/give them the hexunbelts, and also Denton seemed quite informed about magic stuff (e.g. the need to frame Macfinn to cover his trail). Also, we see onscreen that when Harry uses one of the belts he gets an urge to kill. The implication I always took from this is that if he actually used the belt to kill he would have been permanently corrupted...
So granted Lily isn't a scholarly source about NtC (Nemesis-type Corruption), but this does raise the notion that we've seen NtC onscreen before. This leads me to my first WAG:
Basic WAG Theory 1: The corruption you get from killing with magic is Outsider-based.
...and the more radical form:
Crazy WAG Theory 2: The corruption you get is not only Outsider-based, but is actually Nemesis itself.
There's not much proof I can offer for these, but consider:
- Only mortal magic corrupts when used for killing.
- Only mortal magic can summon Outsiders.
Here's another interesting point:
- Outsiders have apparently have some natural immunity to regular mortal magic. If this is because they are the "source of magic", then this would be similar to the natural immunity Winter Fae have against cold, etc.
Crazy WAG Theory 3: The Laws of Magic are all anti-Outsider in origin
We know the Original Merlin (who apparently knew a LOT about the theory of magic) wrote down the Laws of Magic. If Outsiders are the source of corruption, then all seven Laws might originally have been anti-Outsider laws. Heck, even the law against time-travel might be Outsider related, because we see how they used time-magic to attack the prison on Demonreach.
Crazy WAG Theory 4: The Blackstaff can cure Nemesis corruption.
When Ebenezer uses the Blackstaff at CI, we see those black-tendrils curing him from the corruption. Call me crazy, but those black tendrils remind me a lot of the description we get of Mordite and the Mistfiend at the end of Turn Coat (which Harry reminds us was an Outsider). If the two types of corruption are similar (or identical), then it makes sense that the Blackstaff can cure Nemesis corruption.
For more possible evidence, consider also that the only "onscreen" cure to Nemesis so far is Lea -- cured by the Queen of Winter, who is also in charge of the defense against Outsiders. If the Blackstaff really is Mother Winter's walking stick, then it certainly makes some sense that it would have anti-outsider related powers (similar to the "Unraveling"?). The cure for "normal" magic corruption might just be a side effect...
Crazy WAG Theory 5: The Blackstaff itself was the true target at CI
Another implication is a renewed look at Changes. I personally have never been happy with the notion that the Red Court all got together to throw a super-uber-massive spell just to kill Ebenezer. Sure, he was a powerful wizard, but it still seemed like overkill. If the Blackstaff is really an anti-Outsider weapon I could totally see the BC manipulating the Red Court into using overwhelming force against Ebenezer, knowing that in doing so they achieve the true target of getting the Blackstaff out of commission?
Crazy WAG Theory 6: Faith/Faerie magic works fine against Outsiders
While regular magic reportedly has a hard time hitting outsiders, we have seen that Michael didn't seem to have any difficultly in PG. It is possible that this is simply because Michael gets unlimited powerups while "on duty", but note that the Wild Hunt didn't seem to have any particular problems with the Outsiders either. In PG (or maybe BR?) Bob says that faith magic "is on a different wavelength" than regular magic is . I propose that because faith magic comes from faith (or WG/soul/whatever), it is sufficiently different and can thus hurt Outsiders normally.
...And this brings me to my final WAG:
Super Duper Crazy WAG Theory 7:The reason a "starborn" can hurt Outsiders is because his normal magic incorporates an inherited amount of Faith magic in it.
One thing we have heard over and over again is that Harry's father is "a good man". It has long been a theory of mine that one of the criteria for becoming a Starborn is to have one parent a wizard and one parent "good" (similar to the cleric+magic user thing from D&D).
If faith magic allows you to kill Outsiders more easily, then this actually makes some sense as you can "infuse" your regular magic with "good stuff", and hurt Outsiders even more.
- My guess is that having "good" genes is only one of the criteria (perhaps being born in the right time?), and even that only gives you the potential to be a Starborn. You still need to follow up on your inherent "goodness" (whatever that means) before you can become a true Starborn.
- Note that if this is all really true, then Molly is also a potential Starborn, giving Winter a real advantage in any upcoming confrontation.
hehehehehe...