Ruminating on dead places
We're in a city full of towering blocks of buildings, massive tombstones on the grave of the Dead God. The streets are narrow and hold a heavy silence lifted only by the shuffling of dessicated feet. Everything looms. Before you your breath freezes in the air, the only sign of life this place has seen in centuries. A valuable commodity for the factions still skulking about.
The king, who hasn't moved in centuries, contemplating his next move while his court waits and plots.
The priests, who undermine the city with the raised dead of the cities past. They will find a way out.
The general, freshly returned from confinement in the Death Frost mountain. In his memories this city never died.
The dwindling population of ghouls packing out the slum. Never truly dying yet possessed by a fierce hunger. The strongest force the weakest to breed, feeding off their young.
Why would the players wander through this progression of awful things? What do they have to gain by entering each and every building in this city? Why, to kill death of course. But we don't have to turn over every stone for that. Broad strokes will serve, they'll fill in the gaps and let us know when something awful needs our attention. Here we find a trap, an encounter, an interesting thing. We know how they link together, we track a rough trajectory and ignore the nuts and bolts. A city isn't packed to the rafters with pertinent content, a city is a series of events, a flowchart or pain that can be created on the fly and run from a huge list of interesting things, small vignettes of soul-rending horror.
It may not be a priority to make deeply simulated structures for every inch. It might just be enough for us to know that the Duven'Ku live in towering stone buildings, one on top of the other in warren-like apartments, life imitating death. Packed in tight.
All we need to build are the choke points, be they physical or plot related. The gates, the monuments and landmarks, ruined buildings that block the way (there was a war!). The building that holds the skeleton whose hand has been carved just so and opens the gate to the sewer, the ghoul king, the Sleeping Queen's wig, the emerald studded maguffin! The players progress through them getting closer to the core of this place. Or dead.
Curated hubs with meandering random encounters connecting them.
As for Duven'Ku himself, the players don't know what will happen by killing him. Or even if they can. To make it even more fun, neither should the GM. Generate that bad-boy. Reach for a table full of interesting possible results of finding Duven'Ku. Maybe he really is dead. It would make sense after all. Maybe he's withered and weak, maybe he's a mindless ball of energy, maybe he turns you inside out, maybe he's not even here?
All this for a little necklace!