Fierce Deity Sword

The Double Helix Sword is a sword from The Legend of Zelda: Majora's Mask. This two-handed longsword is used when Link uses the Fierce Deity's Mask to transform into the Fierce Deity. Aside from its long range, the Double Helix Sword is able to fire magical light blue-colored blasts shaped like buzzsaws, similar to Sword Beams, when used while Z-targeting is in effect; however, each such attack drains one point of magic from the Magic Meter. The sword cannot be unequipped until Link removes the Fierce Deity's Mask.

The Double Helix Sword deals the same amount of damage as the Great Fairy's Sword. The sword cannot be sheathed, unlike other swords that Link can use, but will be put away for the portion of time Link attempts to use a bottle. Link can use the Double Helix Sword to parry a small range of attacks, such as basic whip slashes from Majora's Wrath.

Hyrule Warriors
The Double Helix appears as part of Young Link's moveset. Naturally Young Link will use the Kokiri Sword but when using certain attacks he will transform into Fierce Deity and use the Double Helix sword. Two more unnamed variations appear corresponding with the Furious Deity and Vengeful Deity weapons, though they share the weapons Double Helix blade design.