Acererak's response to the nuclear fallout around the godspires is twofold.
There are those communities being helped by the celestials and other misguided emissaries of the good nations. Wherever they are found to spread healing and comfort, a strikeforce of Acererak himself, together with several fell great wyrms will hurtle screaming out of the deep ethereal and hit the unsuspecting benefactors, leaving only a charred spot, some fluttering feathers and tales of the horror of Acererak among the populace, coupled to a warning about accepting the celestials' assistance.
Less than half a minute after the attack, the strikeforce will have departed back to the ethereal plane, leaving nightmare in their wake and preparing their next raid.
The communities who have not been helped receive a visit from a cleric of Pelor, calling himself Annatar, the Lord of Gifts. He appears fair to the eyes of men, and calls to the people to bring him their suffering friends and familiy, the ones yearning for a quick death and an end to the pain and agony.
When brought before him, he will lay hands upon their bodies, after which a great peace comes over them, and their last breath is a sigh of relief, even as their bodies dissipate into nothingness.
At each town he visits, he makes the same address:
"You need never suffer again, my friends. You have no hope in this world, only to toil painfully towards a meaningless death. I offer release! Embrace the afterlife and attend your God. You will live on, forever, in perfect bliss.
Send word to the other settlements. They have but to call, and I will take away all the pain. Tell them to call for me, to call for Annatar, and I will come. Blessed be, children."