Item from The Stormlight Archive by Brandon Sanderson
The magical bond between a spren and a human that grants Surgebinding — requiring sworn Ideals, deepening with each oath, and killing the spren if broken.
The Nahel bond is the engine of the Knights Radiant. A spren — typically one of the higher orders like honorspren, Cryptics, or cultivationspren — chooses a human who embodies their order's ideals. The human swears oaths specific to their order, and each oath deepens the bond, granting greater access to two of the ten Surges. The First Ideal is universal: 'Life before death, strength before weakness, journey before destination.' Breaking the bond — through betrayal of oaths or spiritual collapse — kills the spren, transforming it into a deadeye. This is what happened during the Recreance, when the Knights Radiant collectively broke their oaths. The mass death of bonded spren traumatized the surviving spren population for millennia. The bond is not a tool — it is a relationship, with all the commitment and vulnerability that implies.
No physical form — the bond exists as a connection between Realms. Its effects are visible: the Radiant gains glowing Stormlight-infused eyes during Surgebinding, and the bonded spren becomes increasingly visible and coherent in the Physical Realm as the bond deepens. A broken bond leaves the spren as a deadeye — a mindless husk wandering Shadesmar.
Also known as: Nahel bond, the bond, Radiant bond