The condition is not infectious neither transmitted. The agent is present in every family directly related to drakes. It develops from the inside, like cancer.
The Earth's calling after every drake family when they reach, in average, the last 20% of their life.
The first physical symptoms are muscular joints becoming stiffer. Added with the usual maximal weight they reach past adulthood, this affect greatly the wings when the species has them, making flight harder to a point it becomes impossible.
The color of the drake scales and leather will become greyer each passing year, losing making them harder to reckognise by color.
Over time, movement becomes way more complicated.
Due to the debilitating nature of the condition, most high intelligent dragons will experience dementia and anxiety as they feel their death is coming upon them soon. This may trigger reckless and violent behaviour they would have usually refrained (think a bit like suicide by cop, but suicide by hero/army).
The only treatment known to most is the consumptions of pure mana energy, which is usually simpler for dragons having a hoard, but some may be reluctant to consume their hoard for extra time. It is a disenchanting process most dragons this age knows, however, less intelligent sub-species may know know it, like drakes. It however only alleviates the symptoms, and do not remove the condition in any way, only slowing it.
This condition is known to trigger desire through some intelligent dragons to reach undeath solutions like lichdom when they become mad enough.
At the end of the course of the condition, the dragon will undergo a petrification process of it's body, transforming into a statue of rock, and losing all life sense.
After a the week it is fully petrified, the dragon statue will wither and disintegrate into powder, getting fused with the earth they choose as their death ground.
Old venerable aged drakes and their cousins, in any gender, type and region.
One of the most known first cases was a case of fraud. Prince Llamir of the FrostBrands claimed having killed the ancient dragon Hilrog'har by himself to claim as a kingship boon. However, he came with a odd "smaller than expected" skull which trigger the High Witch Spopovyr's suspicion. In an attempt of courage, she went to investigate the cave, only to find the dragon was in a stone statue. Llamir took only profit of the dragon's death. The skull was a trophy the dragon kept in their his hoard.
When it was discovered, he was judged by the council of chiefs and exiled. Through a bit of study, Spopovyr shared the knowledge with tribes over the rest of her life.
The only group having a particular interest outside the victims themselves are some sects of necromancy, which can take interest and try to offer undeath to a dragon. This is a way for them to gain access to loyal and very vicious followers, as well as massive fundings by taking the undead dragon's hoard. But most dragons having still a sense of pride will reject this offer with the retalation they can still manage to do. It is a very high reward, very high reward for those sects.
Interesting! I like how the dragons turn to stone at the end of the disease's progression. Makes me wonder if there's a supply for dragon-stone (or whatever you call it) for non-dragons, as messed up as it may be. You also don't hear about dragons being affected by sicknesses much. They're always these semi-divine, larger-than-life creatures; sometimes its nice to bring them down a peg or two. You say its cause is divine. Can you elaborate? That sounds really interesting. Also, I would suggest adding a little more text to each section, breaking it up with pictures and quotes, or just combining a few if they're similar enough. That way, it looks a little better and is more fun to read. This article is really helpful: https://www.worldanvil.com/w/the-grand-grimoire-qurilion/a/q27s-quest-for-world-building3A-formatting-article This one too. https://www.worldanvil.com/w/araea-qurilion/a/summer-camp-20193A-how-to-get-noticed-during-camp-28and-beyond2129-article
Hello L.C ! Great help for the links ! i was trying to find nice format ideas the enhance the reading and user experience. that will be super useful. As for the divine cause, it is linked to the concept of the planet itself they are in. I don't think i will have time to develop it enough to my heart's content, but it is surely something i'll work on or at least try to develop a litte. Happy SummerCamp !