Sword Breaker appears to be an ordinary dagger with a saw-shaped back portion. Despite its low offensive abilities, the Sword Breaker can become a powerful blade when used properly. When in combat, the Sword Breaker can be used to parry an opponent's weapon. If the back portion of the blade is used, it gives a slight bonus that increases the chance of destroying the opponent's weapon.
- Kirito experimented with using this weapon, but was unsatisfied due to its low offensive ability in battle.
- A Sword Breaker is Philia's first weapon in Hollow Fragment.
- A Sword Breaker is available for purchase in Agil's shop in Lost Song for 8,000 Yrd.