The Free City of Yllaphron has taken the name “City of Dead” after the party unknowingly released the Apostle of Kyuss, an enhanced ulgerstasta. The party fled before they could be connected to the disaster, but 10,000+ souls out of the 30,000 population became undead either immediately or in the aftermath. The rest fled. Some months later, the party quietly returned to the city to find a lackluster crusade in progress, just barely. The party organized defenses and led a strike into the collapsed arena to find a prophesized weapon to rid the town of evil.
They found and killed Bozal the necromancer who created the Apostle and released a demon who said he was the weapon the party sought.
The party tracked the ulgerstasta and without much help from the alkilith demon, destroyed the worm. The demon, freed from his prison and with his hatred of the undead worm slaked, has disappeared. In any event, the crusade can now begin to make some progress and it shouldn’t be too long before sections of the city can be cleared. but it will be years before it rebuilds completely.