What was the deal with Hades wearing a crown made of orbiting mordite stones? It definitely seemed like an Easter egg but I’m unsure of the implication. Mordite has a strange story in the Dresdenverse - the only other times we see it in action prior to SG are in DM & TC.
Death Masks
It seemed like a strange, cavalier use of what is essentially an unbelievably radioactive alien material. My tangential WAG here is that Ivy suspected Nemesis had a hand in the Ramp/WC war, so she used a substance from the outside to see if either Harry or Ortega were Nfected (since they were instrumental in instigating the war).
Turn Coat
Peabody lets loose a cloud of mordite-infused mistfiend inside the White Council chamber to devastating effect. The cloud (which had been contained in an ink bottle) requires the entire Senior Council to contain it. This more the type of use one would think mordite would be put to.
Skin Game
Hades has little mordite stones orbiting around his head like a crown. Not much more is said about it, although it gives Harry pause. I don’t believe that Hades was the God of Death, simply the Underworld, so while there is a link to a stone of instant death, it’s not quite linear.
Perhaps Hades is showing his mastery over everything in his realm by using the most lethal substance in the Dresdenverse as ornamentation. Perhaps he can use the stones the way Yondu uses his arrow in Guardians of the Galaxy, so they are weapons.
Perhaps prior to the Aesir/Jotun, it was the Greek Gods who guarded the Gates & Hades was involved in dealing with the Outsiders directly. The stones are a remnant from that time.
Perhaps the stones have a higher, more spiritual purpose than simply killing. Maybe you have to be a God to be able to use the stones in that way.
