The collective of dwarven craftsmanship
While knowledge is a thing that one can store and collect, craftsmanship is uniquely tied to the craftsman. It is a fusion of knowledge, intuition, imagination and years of practice. When the craftsman dies, only their knowledge remains, but the rest die with them. This was a problem that a couple of dwarven wizards faced hundreds of years ago: How to continue to evolve their fascination with magical construction?
Their solution was also their own crowning achievement: They built a masterwork forge on top of a volcano and infused themselves in it, creating a collective of their abilities, albeit at the cost of their individuality. They gave it a name that they hoped would become the new synonym for perfection: Umura. It was a hidden beacon, glowing to only those who the forge deemed most skilled and worthy craftsmen of dwarfdom. These people would seek it out and give themselves to it, benefiting and adding to the collective knowledge.
But crafting for its own sake is a folly, as the most highly-regarded belief of Umura is that form must follow function. That is why it creates items destined for legendary deeds. But it also recognizes that it needs materials and its craftsmen need food. That is why it also keeps a steady supply of gold by allowing great people to order items for lesser purposes.
Umura, as a collective will, is also somewhat disorganized and self-contradictory.