Integrate poschengband mechanics into DDA:
Hulks, brutes, masters and necromancers gain fire breath weapons and summoning. Summoning can summon other hulks, brutes, masters and necromancers
Unique, named zombies with health in thousands
Disenchantment - damages even power armor
Britain mode:
No guns spawn
No dedicated weapons spawn, only tools that can be used as weapons
Australia mode:
Like Britain mode, but with way more, way bigger spiders