"The long and short of the story is that I was about to complete the game and saved, noticed that I was able to use Lloyd's Beacon in the ending room and since my lich was pretty high level with water magic, the Beacon duration was well over 200 days which seems to be some threshold.
The older Beacons with less duration did get wiped but the newer ones I made managed to endure the new world wipe (when I first finish the game) and I ended up with the ending room location in my Lloyd library with 1800 days duration. I then teleported there to see what's up, walked into the light and finished the game the second time in 0 years, 0 days and 0 hours.
The Lloyd's Beacon duration bug also allowed me to prepare other interesting locations into the library for the start of the next game, like visiting Celeste without being Light/Dark. Curiously enough the Archangels didn't take too kindly to my presence there and were very hostile."
From ever ongoing discussion from Might and Magic 6, 7, 8 merge based on mm8 engine thread.
Courtesy of Thonkerton. Thanks!