Ridill

Riðill (anglicised as Ridill) is a sword which was in the dwarf Reginn's possession in Norse mythology.

Under the guidance of Reginn, Sigurðr slays Fáfnir, Reginn's older brother who murdered their father Hreiðmarr and transformed himself into a dragon to monopolise all treasures. According to Poetic Edda, Reginn used Riðill to rip out the dragon's heart. However in the Vǫlsunga saga, it was Sigurðr who cut out the heart with the sword at that occasion.

Incidentally, the sword is called Refil in the Skáldskaparmál, written by Snorri Sturluson.

In popular culture

 * Riðill is classified as the Class Champion Weapons in the video game Granblue Fantasy.
 * Riðill and Hrotti are wielded by Saber/Sigurðr along with another two unnamed daggers in Fate/Grand Order.