The original idea was to make a fantasy trilogy, each comprising a different tone and subgenre.
The Stone of Brimisvallir starts off as a mystery, with a lot of focus on building tension, which later bursts and evolves into an action thriller. The Butcher of Allasar is a bit slower, focusing on drama and the characters' relationships, showing how the Revenants interact with one another.
The third and final novelette, which will be called the Crystal of Farstead, will be a pure adventure, following the Revenants through Dealwen as they keep finding themselves in ridiculous scenarios. While the tonal shift in the Stone of Brimisvallir is treated more like a revelation, and the progression of the Butcher of Allasar more like a descent into madness, the Crystal of Farstead will contain a proper twist.