I'd love to know exactly what Butters was looking at after Harry made that ice block to Dave them on the waterfront. That's probably the deepest he's ever drawn it in and used. I imagine in my head some wicked version of old man winter lol
I don't think it's precisely a battery tho. Even if that's the basic usage Harry can see for using it. From how it's described, I think it's an active channel TO Mabs power source. His limit's are potentially only her limits as far as raw power. He'd just have to give himself over enough to winter and have the precise ingenuity of how he planned on using it. It may, probably, kill him to push past a certain limit. Though that'd depend on how he manifest that energy. Through spell work? Yea, he can only personally gas so much before he's drained. Mortal an all. If he was just using himself as a raw conduit for it, more similar to when he took on Maeve in CD. Then he might be able to handle it. Though what'd he manifest as is up for debate. Something like the snow monster from frozen lol.

Harry is making a mistake accepting too much of what Butters theorizes.  Butters is the one who gave Harry a reverse magic feather by explaining that the Mantle just hijacks his pain thresholds.  Butters had seen a lot by then, but not nearly enough to be a magical, but not magic consultant. 

In the Lake, Butters is doing some quick math.  Phase changes -- ice to liquid/liquid to steam -- represent absolutely stupid amounts of energy.  He has just realized how much ice Harry made in just a few seconds to float half of a sunken warehouse to the surface and it probably compares quite favorably to a small power plant: 

According to Wolfram Alpha it is about 3.19 x 10^6 KJ (to freeze 30 tons of water), and if it took 30 seconds that works out to be .1 Mega Watts. 

So, yeah that's a crazy feat of power all things considered 

Can Starborn be Nemesis infected?  I thought that they couldn't be affected.  That's why Justin was so keen on having Harry and Elaine -- two Starborn wizards that obeyed. 

I wonder about this scene.  For Murphy to have broken the sword, did Nicodemus have to be sincere in surrendering the coin?  I would think a false repentance to be particularly blasphemous and so Nicodemus would have earned any judgment inflicted by Karen. 

I'm not sure about this, but I seem to remember a WoJ that said that Harry is actually good at Water Magic too, but really hadn't received much training in it and so doesn't think he's good at it.

I feel like this is the hinted at "back to school," thing that has been foreshadowed where Harry trains with River Shoulders and maybe learns some shapeshifting.

I'm in camp of the Whamps starting as a Wizard's deal, made by an ancient Etruscan wizard looking for a pathway to immortality. 

As for the Ramps, it support it depends on whether one considers the Red King and the Lords of Outer Night as simply the very first humans exposed to the Ramp "pathogen," or whether they were actual denizens of the Never Never that relocated here. 

His contract was actually fairly specific, and he also carefully devised an escape mechanism -- he arranged his own murder and had Molly erase the memory.  This speaks to his careful planning. 

I withdraw the accusation of stupidity, since Harry didn't think the money would matter since he was going to be dead (one way or the other) afterwards. 

Not so (for the first bit).

The Etruscans were essentially contemporaneous with the ancient (pre-Republic) Kingdom of Rome; the Republic stage of Rome saw the end of the Etruscans as rivals of theirs.   The Romans definitely borrowed from the Etruscans (several loan-words have been documented, for example).  It may well have gone both ways, but we know a LOT more about the Romans.  Etruscan "borrowings" from Rome -- if any (I assert the extreme likelihood thereof) -- are AFAIK lost to the ravages of time and Empire.

Mycenean Greece predates both; then Greece had a fragmented "Dark Age" for some centuries.  The "Archaic Greek" era and the rise of the "Polis" city-state model in Greece was, again, roughly contemporaneous with the early Etruscans & Romans.

(I am unclear how much of this historical trivia is relevant to the Dresdenverse; but, see below!)

This is... an excellent point.

Given that we learned relatively long-ago that the Whamp "court language" was Etruscan, the lack of further info is indeed "suspicious" (OTOH, I wouldn't put it past Jim to simply be holding this back in order to provoke speculation, as a red-herring sort of thing).

We haven't deciphered much of Etruscan as of yet, but I think they are hopeful a they find more stuff.

I think it is interesting that we know very little of White Court origins.  I suspect that they are the offspring of a powerful Etruscan wizard that "did a deal."