I did search this, so excuse me if it's already been posted, but I didn't find anything.
My idea is simply that, in adventure mode, you can permanently destroy a town. I *think* this is achievable currently by destroying that civilization, but short of that, you could simply add a new action, allowing you to torch buildings, or otherwise destroy them, and then the town would cease to repopulate. I destroyed an entire goblin village only to die later, make a new adventurer, come back and find it repopulated. To even it out, you'd only be able to destroy buildings once their inhabitants are dead, the action to destroy the building would take quite some time (or require several button presses) in which time the inhabitants would come out in arms and attack you to defend themselves.
Of course, if you are a Legendary Dodger with <<*Candy Armor*>> then their plights are beneath your worry.
If you have any ideas to add to this, let me know, I'd be more than happy to hear them