Really just kinda a self indulgent mini Worldbuild. Not meant to be for any specific setting but rather a bit of lore that can be slotted into any setting! Sorta like a module you can nail onto something.

Most of the basic concept is in the image so ill just expand on it here

The idea is this dead dragon can wind up anywhere in a timeline or in another realm entirely. Could happen to our world! Or could happen in the stone age of our world! Or it could happen in some other fantasy world, or deep into the high tech future of that fantasy world. It can show up just about anywhere at any time, and even appear both in the past and future of a timeline when those times come.

So the radicals the Sooten of Yurn recruit can often vary a lot. If you're dealing with a Yurnic incursion in our time and place, expect the fanatics who join them to perhaps be turncoat soldiers or, more likely, insurgents. Utilizing modern rifles, drones, technicals, etc. If its in the mid 19th century? Expect some yeehaw fanatics.

But of course these kobolds still generally have free will, so I would imagine more tend to just try and keep away from trouble than most. That said I would also assume they may have a strong impulse for a couple days to sting others, the influence of Yurns Curse to sting and transform others could likely be resisted with some good old fashioned willpower, though could be difficult. But I would imagine after those couple of days, the impulse would die down and, while the stinger would still work in transforming others, that kobold would have less of a drive for it. From there they're on their own unless they either join or are taken by the cult.

Lastly this curse is not unstoppable as while Yurn was a very very powerful dragon, they were not a god. So people who protect themselves with powerful magics and/or technologies could in theory resist or at least slow down the effects of Yurns curse. Though for the average person they're pretty defenseless.

Not too much more, again this is more meant to be a thing that varies in the realities it winds up in so take it with salt!

There is the Beach that makes you Old
and now
there is the Body that makes you Kobold

be well