A blade forged from obsidian, in the heart of a great volcano.
The KotHaar of Ashenfall are ancient beings, whose existence dates back millennia ago to when the elder gods first created the region. At the end of their lives, they would take themselves on long pilgrimages through underground tunnels, back to the mainland, where they would be reborn anew in the Elder Kiln.
Fuzan put a stop to that, by destroying those tunnels.
Once these obsidian swords would have been reforged alongside their owners, each sword containing the ancestral memory of the swords that went before it. They would absorb fragments of KotHaar knowledge, learning, in their own strange way, how to be better weapons.
These swords are not alive, in any true sense. There is no soul within them. No mind you might ever speak with. But the KotHaar and their kin are strange creatures, born of fire and stone, so their weapons carry some of that strangeness with them.