The Tyrfing is a legendary but forbidden magical weapon housed by the Erudon Family and only wielded by Abyss Knights. It is said to attain immense power, but also holds a curse: the blade amplifies the user's powers when his or her are at their weakest, but at the cost of their lives. The sword can only be held by special gloves that nullifies the Tyrfing's curse.
- A Tyrfing (or Tirfing) is initially a magical sword that is figured in a poem; a cursed blade that forces the user to kill someone every time it is drawn.
- The Tyrfing's description may be a reference to the poem, as nearly everyone who wielded it supposedly died.