Item from Steelheart by Brandon Sanderson
Every Epic's Achilles heel — a specific, personal vulnerability that temporarily negates their powers, always fear-based, always unique, and always the key to killing them.
Epic weaknesses are the Reckoners' reason for existing. Every Epic — no matter how powerful — has a specific vulnerability that temporarily strips their powers. The Reckoners' methodology is: study the Epic, identify the weakness, build an operation around exploiting it, kill the Epic while their powers are down. The weaknesses seem random (why would Sourcefield be weak to fruit punch?) until the series reveals they're all fear-based — each weakness is connected to the Epic's deepest personal fear. And ALL of those fears are actually fragments of Calamity's fears, distributed across his recipients. Megan's discovery that facing your weakness overcomes the Darkness reframes the entire concept: weaknesses aren't just vulnerabilities to exploit. They're doors to freedom. Every Epic who faces their fear instead of fleeing it can use their powers without corruption. David's notebooks — years of catalogued weaknesses — are the most dangerous non-Epic weapon in the series.
No physical form. Weaknesses manifest as specific conditions: UV light for Nightwielder, fearlessness for Steelheart, fire for Megan, failure for Prof, compliments for Newton, Kool-Aid for Sourcefield, dogs for Conflux. The diversity is absurd. The consistency is absolute: every Epic has one, and finding it is the Reckoners' entire strategy.
Also known as: Weaknesses, Epic Vulnerabilities