ToME WikiOnly accessible to the lost soul subrace.
Unique monsters are never generated in The Halls of Mandos (as far as I can tell), though they can be summoned as per usual; thus, genocide is more useful here than elsewhere. Dungeon towns can be generated, but don't count on it; none of the several Lost Souls I have escaped with ever saw one, although a few who died on the way did.
See the subrace spoiler Spoilers/Subraces/Lost Soul for tons of tips for surviving twenty extra turns or so in this near-hopeless environnement!!!