Clay Golem Odem

The Odem

"A golem's heart does not beat. It is still found in the rubble, long after everything else."The odem is the golem's heart, a sphere of steel made of nested discs, each covered in arcane signs. The signs decorate nothing: they tell the matter what it must become, a thing that lets itself be led, and it is in them that the golem's missions are written. The smith who carves them must be a master. One sign left open, one stroke cut too deep, and the whole sentence changes meaning, on discs that fit in the palm of a hand.
Every golem has its own. The odem answers to the circles the sculptor set into the clay, and in another body it would find no one to speak to.
The final touch belongs to the mage. He sets the odem at the center of a circle that channels one or more planes of matter, the plane of Earth for clay, and charges it with their energy. That is when the sphere stops being a piece of smithing. It will not make the golem beat; it will make it obey. Whom it obeys, the control ring will say.
When a golem falls, the clay shatters and the odem remains, whole among the shards. It takes a master to forge one, and far more to unmake one: neither hammer nor forge fire can get the better of it. It will never serve another body, but mages pay dearly for it, to take it apart and read, disc by disc, how someone else taught matter to obey.