NOVEL NEXT Interlude: The Fall Of The House of Kholoth
The explosion which results from Quint Aumraham's little science experiment has a pretty large number of consequences; it practically vaporizes the Forest of Corpses (and every last man of the Sheonn Army with it), boils most of the water in the Swamp of Drowned Men, and destroys the Black Gate utterly (which is a shame, because it was a very fine example of good craftsmanship and themed architecture). Dragon Valley survives mostly unscathed, but southern Thoxen and Virtuous Pioren don't; the overpressure and blast wave devastate mile upon mile of countryside, obliterating several dozen towns and a handful of larger cities. The consequences of this will be pretty dire (especially since it will be some time before anyone discovers that not all of the forces of humanity were obliterated in the cataclysm), but all considered, things could be worse; Kelfir Leafwind, for example, is nowhere near the battlefield and thus doesn't die horrifically as he would have otherwise. Similarly, the damage to the mortal nations' economies and infrastructure, while catastrophic in the extreme, does not plunge their entire civilization into chaos; the elves, in particular, have lived through this sort of thing before and have a pretty good playbook for rebuilding society. Things will be very nasty for a while -- lawlessness, slavery, and cannibalism in particular can expect a brief heyday for a couple of weeks -- but things will eventually get back under control. The secretive fifth nation of the world is not so lucky.
With Tyal Ex Zedeus' death and the obliteration of the demons' entire army (including all of their reserves), tensions back home erupt quite violently; the stress between Hox Manceris and Zum Velbat finally boils over into outright hostility, and there is a short and very exciting triple coup d'état as Kholoth Rael Kheshnagon, his ears deafened to the cries of his people by the simple expedient of being muffled by Suzume Saiki's thighs, fails utterly to do his job and the nation of the demons collapses into anarchy.
Vius Mak Ghiroth, Wielder of Fortunes, Prince of Spies, Betrayer of Kholoth and Lieutenant of the Demon Lord, is the first to bail out; he was already packed and ready to run anyway, and when things between Zum Velbat and Hox Manceris get particularly heated his famously shaky nerve fails him -- he lights out for the Wall of Lost Hope almost before the news breaks, so he doesn't get to see how everything plays out. Zum Velbat, who has a pretty good run, nevertheless eventually must confront the fact that knowing the future is not terribly exciting once you discover your future is to die at the hands of an impossibly complex and clever stratagem authored by your opponent, whose literal job is killing people exactly like you. Though a capable plotter and schemer, Zum Velbat (Gazer of Sins and First of Diviners) is not a soldier, and it is this which leads to him being cornered and executed by Hox Manceris (who does not bear the title of Harbinger of Slaughter lightly); he has a pretty solid death, spitting out a final curse of violent demise at his opponent, who appreciates the artistry and salutes the liquefying remains of his quarry respectfully. He lives less than two hours afterward, because when Kholoth Rael Kheshnagon finally comes up for air long enough to discover what has happened to his kingdom, he does not waste any time before holding those responsible accountable.
Almost before the dust has settled from the explosion of what will eventually be called the Last Battle of the Demon War, the nation of demons is a shambles; children weep next to the empty chairs of their classmates, parents do not come home to make bloodflesh sandwiches, and the (very few) remaining who remember the time of Kholoth's grandsire bemoan the fall of their glory before being put to the sword as Kholoth Rael Kheshnagon, Monarch of Fire, Bloodstained Lord of Unforgettable Sorcery and All-Seeing Keeper of Fears (and his new queen) consolidate their power and thoroughly eradicate dissent. Stock is grimly taken among the ash and ruins of their society before the absence of Vius Mak Ghiroth is detected; and, as a last prelude to the final efforts, Saiki Suzume volunteers to collect him and bring him back for their particular brand of what they call justice.
She'll have quite a chase.