The Idea Factory - The Destiny of the Sword

Factions of non humans hiding among the humans. Most of them are huge families spanning multiple generations. Each faction owns one section of a city, with each section being waled off from each other in something of a maze so that the factions can only reach each other through one section where the keeper of the sword faction lives. At the center of this are lies the sword. It starts off dormant, it's pieces separate and locked. The keepers had been getting the MC's faction leader to make the keys for it. When their leader realizes this he goes there alone, unlocks the sword, and places it in the receptacle that would grant him power and control over the region but he doesn't turn it. He knows that claiming that power would unlock a prophecy about the north invading. Since the faction is neighboring the north, with their factions still divided, they wouldn't survive for long. The keepers of the sword want to trigger the prophecy because reasons. So, they kill the leader. Which sets off the main events of the book.