I think Blades play, both orthodox RAW and its short, freely available expansions, allow for a much wider range of genre and tropes than you imagine,
@AbdulAlhazred.
In one game,
@Nephis and I played a Cult, whose primary objective was to heal the fracture between the realms of the living and the dead by bringing forth our goddess, a Raven Queen analogue, into the world.
Later, when those primary PCs were sacrificed in the cause of the Crew's agenda, we played a short-lived game of Vigilantes, NPCs betrayed and disgusted by our original Crew, seeking to exact vengeance upon the various cults that have been preying upon young mystical prodigies as conduits for bringing their forgotten gods into the world.
Now, we're playing a Crew of Inspectors,
True Detective- style investigators of the murders and disappearances in the orbit of these child abductions in Doskvol. While these latter two games
do involve slight additions/alterations to the rules set, they are far more along the lines of 4E's introduction of a variant resource management for Psionic characters in PHB3 than a true hack, retaining nearly all the architecture, if slightly reskinned in places, of the original
Blades in the Dark.