What would you want for a 4th Kingdoms module?
Imo a Colour of Madness module would be peak, I want to see those enemies in DD2's improved graphics amd combat system. And imagine if there was a unique mechanic of the spreading corruption. Comet lands somewhere at the start and slowly spreads, replacing the biomes around it with its own Blasted Heath type biome, with more dangerous enemies. Though I'm not sure how this'd work for the small Kingdoms maps.
I'd also totally love a true endless mode for the game. Getting a Colour of Madness themed addition would be a good excuse for one, whether it's endless combat like DD1 or a new version where it's endless regions