The Stormlight Archive, Books 1-3: The Way of Kings, Words of Radiance, Oathbringer

by Brandon Sanderson

“So they’re all spren,” he said. “Shardblades.” Syl grew solemn. “Dead spren,” Kaladin added. “Dead,” Syl agreed. “Then they live again a little when someone summons them, syncing a heartbeat to their essence.”