There was something special about the way the human Heralds interacted that could lock the Fused on Braize, the land called Damnation by the humans. Only once the Fused broke the Heralds through torture—sending them back to Roshar—could a Return be initiated. This cycle had played out for millennia, until the Last Desolation, where something had changed. Something to do with a single Herald and an unbreakable will.
