Ideas for city threats from Bas-Lag books-
1) Slake Moths. They feed on sentience (leaving a mindless husk), excrete nightmare (usually over the population they feed on to have their food source despair) and most importantly, they feed their young on the concentrated memories of those they’ve eaten. This can be cut with other material and sold as highly addictive drug called “dreamshit”. Other notable traits – they aren’t 100% in our dimension and suffer less damage from every attack, and their wings have slowly undulating patterns on them that mesmerise sentient races (those able to dream). Merely glancing at them paralyses anyone – but they can be looked at through a reflection. May also be used as a final method of interrogation (victim is fed to a moth that is then milked and the memories, while far from coherent, could be experienced).
2) The Construct Council. Constructs, card programmed clockwork, quasimagical, or chemically powered robots are widespread domestic help. Until a artificial intelligence creating virus, propagated by a cult of construct repairmen, starts changing them all into spies. When their masters sleep, constructs gather at a garbage dump and upload their memories to the Council (an amalgum of discarded thinking machines and constructs that act as a single highly intelligent AI). Only a problem if the Council sees the city’s behaviour (or a Faction’s) as a threat to constructs.
3) Spiral Jacobs. A good natured, often incoherent bum that wanders the streets. Named for his incessant drawing of spirals wherever he goes. He’s actually a somnambulist (golem creator) agent for a city that is currently at war with Duskwall and if he completes the ritual, he turns the entire city (or most of it) into a golem.
4) Isaac Dan der Grimnebulin. Anarchist, free thinker, scientist and inventor. Normally not of interest to anyone. Until he invents a perpetual energy machine. Sure the prototype is fragile, requires someone with know-how to start it and burns out if too much energy goes through its circuits. But with improvements, the sky is the limit. So now him, and his machine are wanted by every power in the city.
Slake Moths would be a good expression of a demon or Forgotten God avatar for a Cult gang.
But you have to make the Hypno-Toad noise from Futurama.
They’re from outside the city, imported in especially just for drug production.
Less a threat for an entire city but the Remade could be a threat of what could happen to the players. Someone really good with mechanics could even make a new sheet like Ghosts. It would trigger potentially when you get imprisoned.
You would need to establish them as ubiquitous second class citizens fairly early if you want them as part of the setting. fReemade should also be a faction with their current leader Jack Half-a-Prayer. https://en.wikipedia.org/wiki/Remade
So. Much. Yes.