Just a concept I had to try and help bring more lore specific examples of Sundering, and just an idea thats been sitting in my head since the idea of Cuprophillic bacteria were introduced years ago

That being bacteria that live off of the chemical energy of oxidizing copper, like Ferrophillic iron bacteria in real life.

So here is the pitch

In an isolated basin of the Covoron of Logáu, a strange ecosystem has formed due to the strange geology of the region. With deep high concentrations of copper mixed with a sprawling wetland created by a basin that stagnated a river. The wlidlife in this region, whether by breed adaptation or as species unique to this region or otherwise, the ecosystem has become dominated by copper based plants and animals that used copper, instead of iron, to transport oxygen or to serve other biological purposes that iron would normally serve.

This region, known as Stãtak or literally the "metal basin", is defined by a high concentration of copper, such that its toxic to outside life.

Cuprophillic bacteria and strange copper based plants dominate the landscape, Large treelike ferns, blue algae, etc. all exist on the surface and in the complex limestone cave networks beneath, which are on occasion exposed through collapsing holes in the ground as the stone collapses.

During Logáun hot years, the rain from the mountains intensifies and that water turns this region from a wetland into a shallow sea in which aquatic life thrives. During cold years however it becomes colder and drier, with most water slowly draining into the complex limestone caves below.

During the warm years, arthropods from the deep celestial sea reefs migrate from the deep oceans of the endless sky into the relatively warmer temperate shallow sea.
During the cold year they lay spawn and die, with those offspring traveling back into the deep seas in the next warm year. But during the cold years many of the massive adult, carboniferous like animals are easy hunting... though like everything else, heavy in copper

Enter the locals

One of which helping a Cedunla traveler learn the basics of the region.

During the awakening period of The Quiet Age the region would remain without any permanent éldimor population, with the region being avoided. Though 800 years later the first dens would migrate into the region and in a few generations, a more permanent population of drekir would take hold and the breed would adjust to the intense conditions.
The local breed of drek is of a temperate sort, notably smaller than average, horned, with a particular resilience to copper poisoning (really necessary here).

As of 950PA (817 Logaún cycles) There is only a small tribe, one clan of 9 dens, numbering around 240 drekir.

They are a very distinct, though isolated cultural group with an independent language they refer to as Nur shele which has the unique quality of being a tonal language.

During the warm years of high waters they live highly nomadic lives in specialized rafts built of reeds that they refer to as Balabalá Which are individual living quarters that can be tied together to form larger camps.
These boat camps are even complete with floating pieces of scalewood that have firepits placed on them for cooking as well as floating hatcheries that can be anchored.

During cold years all the dens will gather together and live together in a larger encampment, usually built of treehouses in the soft, giant fernlike scaletrees. With the floors built of woven reeds and the rooves of ferns. Since the 'trees' are flexible they are often bent and secured together if possible, These bent trees form the roof and a floor is woven beneath it, forming a sort of long treehouse. if not then the home is built at the top and a woven net spirals down the trunk to the ground

Industrially they are an example of a chalcolithic culture that doesn't do much lithic

They do not practice pottery nor flintknapping. But their lives are built around skilled weaving and copperworking. With a lot of hide tanning forming the bulk of their clothing with the local amphibians being both a prized source of food. Their blood being a particular delicacy thanks to the high amount of iron in it, which is a rare nutrient in these parts. Most of all the blood and meat of the B'ragãu seen to the right, giant tadpoles

Their metals are derived from resonant sundering of organic materials such as cuprophillic bacteria laden mud, the blood of copper based aquatic arthropods, and mashed up scaletrees and other copper heavy plants.

They utilize raw latex coated amphibian hides to cover small copper plots that are heated over fires and struck with flexible fern batons. This particular setup creating long rods of copper rather than sheets, which they cold hammer on the harder dolomite rocks into knives, projectile points, and specialized chopping tools, like hafted fork axes designed to rip apart scaletrees rather than chop them.

Noone is sure who the original culture they came from was when they settled here, though they share a similar cosmology to neighboring tribes out of the isolated cupric wastes. They believe themselves to be the offspring of a giant subterranean snail who hides in the deep limestone caves beneath them. Both male and female the snail bred with itself to make them, but after an Eb (drek) ate a cupric snail this god, known as gil na se cursed the earth to bleed copper as punishment and fled underground.

But they don't worship this god

the snails are tasty so its worth it I suppose

Instead they worship the caves as they believe thats where spirits go, assuming they are trapped in the verdisgris mud and sink into the caves as spirits when they die.

So these caves, often accessed through deep pitholes in the earth leading into waterlogged caves, are sites for religious rites. For adolescents to become adults it is believed they must jump into one of these caves and sleep there for one night, giving a tribute to dead ancestors by leaving ornate copper rods with intricate patterns carved onto them. It is also common to throw ornate copper jewelry and objects as tributes to the dead during funerary rights and its not practiced by all 9 dens, but at least 5 of them have a practice of burning bodies and throwing the charred bones into the caves as a funerary practice
These folks are also noted to have some nutrient problems... as living in such a copper heavy environment would cause and while they are resiliant to copper poisoining (moreso than most other drekir) they are not immune to it.

Life is often short in this place, due to complications caused by copper poisoning, and it is also quite dangerous. With giant dragonflies being known to maul and predate on drekir, with the locals having a similar relationship to them as one would have with bears or lions.

they are sought after by the brave who see them as enemies of war and during religious rights, the exoskeletons are often worn.

Likewise most of these drekir suffer a lot from iron deficiencies, hence why B'ragãu blood is so prized due ot its (relative) high iron content

but back to the drawing

A Cedunla traveler and scholar of the burgeoning city state of Agumok has traveled out to research the ecology and is staying with the local hunter gatherers. Its a far off land and one that is strange ot them, but mundane to the people who live there
probably weird seeing such a small temperate drek for a cedunla drek that is, on average, slightly larger than other temperate drekir but thats somewhat how breeds work with the new system