Cliff Blight

"You see that, up there? That's right, the red one. Way up by the gull's nest. The one that looks like a bleeding cut. That's Blight. Touch it, you'll burn for weeks. Eat it? Don't make that kind of joke.

Fire Scars

Cliff Blight is a carnivorous plant native to the Pinion in the Skymeet Isles. Cliff Blight is an extremophilic plant, thriving off of the rocky, rain-swept cliffs of the islands.
The plant usually grows in small patches on remote shelves and crevasses on the wind-facing cliffs. In the day, especially in the light of the rising and setting sun, it is easily identified, appearing as bleeding scars across the cliff faces. This red color comes not from the flowers - which are small and yellow - but from the large, flat leaves, which can range in color from a lighter vermillion to the deepest of reds, depending on the plant's maturity.
Because of its living conditions, Cliff Blight rarely is in the right condition to reproduce. Instead, they simply endure, thriving off of the water that runs down the cliff faces, and the insects and small birds that are attracted to their fragrant flowers, which develop sharp spines for capturing prey instead of reproductive organs. Cliff Blight patches can sometimes survive in this way for decades.
In addition to their insect- and small bird-trapping adaptations, Cliff Blight produce nematocysts in their leaves, which inject an incredibly painful toxin into any victim unlucky enough to touch them. These toxins are strong enough to kill a bird in seconds, and can cause anywhere between a week and months of pain for any larger species, including those such as humans or dragonborn.

The Blood of Dead Demons

Like many of the dangers in Ravengrin, there are myths and stories of how Cliff Blight first came to be. Legend says that in the First Days, great wars were fought between the Raven Gods and the demons from below. It is said that after long centuries of unending war, these demons were locked away forever, never able to return to the plains of the living. It is said that in the final days, the greatest of these demons, Asal, was struck down by Fulvens-Seer, and where drops of his blood fell the first Cliff Blight grew.

Cureless Poison

"Woe to any who dare consume the blood of the demons."

Or so it is said by Karsovzi elders.
Cliff Blight, when ingested in its plant form, can kill any creature, man or beast, in mere minutes. It starts with a loss of cognition, followed by violent spasming, sometimes rampaging. The skin becomes a sickly pinkish red, and death soon follows. It is said that Cliff Blight is one of the most painful ways to die, and those that fall victim to it are cremated, their ashes cast out into the sea.
Even more horrifying are the results of failure to properly treat the dead body. For in mere days, a new plant grows within the corpse. As the flesh decays or is consumed by scavengers - some of whom are themselves killed by accidentally ingesting the poison - the red leaves of the plant can be seen growing within. In as quickly as a few months, as the bones of the original victim and any other subsequent ones are picked clean and bleached, large patches of Cliff Blight can form, germinating and spreading outwards at a rapid rate. Such places are extensively burned and sometimes cursed with dark magic, to kill the plant and stop it from spreading.
When Cliff Blight is distilled in boiling water, it can produce small amounts of a far less efficient, but no less deadly poison. The process of concocting this potion is incredibly dangerous, involving building up an immunity to the fumes of the poison over many years before being able to have the direct exposure required to make it. The end result is the ultimate poison, scentless, tasteless, discreet, utterly deadly, and above all: cureless. Nothing but the strongest divine magic - which, in this age, precious few, may none have access to - has an effect on the toxin.
Famously, Yaeza The Tyrant used an entire vial of this poison to kill Karvosta Van, allowing him to wander the land as his mind left him. It is said his death was both slow and incredibly painful.