The Book of Ruin offers a few suggestions about narratives for Chaos-corrupted House gangs, but it feels to me like they went for the low-hanging fruit. In the case of Nurgle, their suggestion was regarding Cawdor, since they basically spend their lives picking thru filth heaps anyway. But consider:
- A Goliath gang who have shifted their definition of strength from what they can overcome to what they can endure. Every time they take pride in shrugging off some damage or pain, Nurgle's hold on their souls tightens just a little further. There's probably also some potential to draw from the line in Hammer to Fall, "Build your muscles as your body decays", but that just popped into my head, so I haven't thought further along that line yet.
- A Van Saar gang, their immune systems shredded by the radiation from their faulty tech, discover that, somehow, the diseases they are left wide open to no longer affect them, even tho they have clearly not been cured by any means.
- Orlocks are kinda Cawdor-lite in this specific regard. Not a whole lot I can think of that's really cool here, just that they probably cracked open something while mining that they really should have left alone.
- House Delaque was created by a plague of dream sickness, which puts them pretty squarely in Nurgle's wheelhouse from the word go. But even beyond that, there are some interesting possibilities. The things they do for the Silent Ones frequently take them to the deep, dark places of Necromunda, where all manner of foulness lurks. Further, the Silent Ones might well be careless about something that was harmless to the original Delaque species, but is highly infectious for humans.
- House Escher bring to mind a subtler taint, reminiscent of the Dan Abnett short story Pestilence. Spreading Nurgle's plagues thru tainted chem deliveries, perhaps even focusing on medical supplies for extra irony.
- Corpse-Grinder Cults: What, you think Khorne is the only one who benefits from a Hive being filled with piles of rotting flesh? The focus here becomes less cannibalism, and more just about gratuitously leaving rotting meat all over the place for decay to take its course. Altho not leaving the cannibalism angle out entirely; perhaps only consuming the dead once they have sufficiently "ripened". The angle for Escher works here, too, spreading the diseases thru the food supply rather than chems. Also some cool potential modelling opportunities using Blightking parts, and perhaps an insectoid aspect to the masks rather than the standard hornéd beast look.
Well, hopefully none of y'all catch anything like this shit I've got, and until next time, y'all have a good one, y'hear!