Zundalon the Cantor died in his bed at sundown on the Day of Mourning Stars, three days into the Month of Elder Wisdoms. His true passing went unmarked in the Year of Retribution Dawning, and no history book would ever record his last words to the ages. Caden himself did not write them down.
"That which is dead can eternal lie,
"For with merciful aeons,
"Even Death can die."
The Cantor smiled when he said it, smiled when he died, and kept smiling as Caden burned his phylactery and cleansed his resurrection pool. Piece by piece, with only the corpse as a witness, the Sorcerer destroyed the last surviving Durklan and wiped him clean out of this world. He brought the roof down on the chamber, slowly but inevitably, and then he scourged the walls of the passage clean on his way to the surface. When he was done, he slammed the while thing shut and obliterated it all, compacting the earth down into a crater within a crater, packing it so tight that it would hold shape, and a small lake might form with a few centuries of rainfall or dumb luck.
He didn't mark Xem'zund's gravesite. He didn't really do anything other than to stand watch for an hour, Hat off, skin alight with lingering Sorcerous power, head bowed with an eerie, disquieting sense of respect.
Then he put on his Hat, changed to his glasses, and started looking for a way out. Hopefully the Skinwalker was busy somewhere else.