Fenrir

The Fenrir (フェンリル) is a Keychain for Sora's Keyblade which appears in Kingdom Hearts II. After defeating Sephiroth in Radiant Garden, Sora witnesses a battle between Cloud, Sephiroth, and Tifa. After Sephiroth and Cloud fly away into a duel, Tifa thanks Sora for his help and gives him the Fenrir Keychain.

The Fenrir is also one of the types of Keyblades left at the Keyblade Graveyard.

Design
The Fenrir Keyblade takes on the appearance of a pin tumbler lock key, with bandages adorning the base of the blade similar to Cloud's sword. Because of the styling, it is notably the only Keyblade with no "teeth". Its Keychain resembles Cloud's Fenrir pendant from his Advent Children outfit (also a reference to the wolf-god, Fenrir).

Fenrir is named after the motorcycle ridden by Cloud in Final Fantasy VII Advent Children, which also appears as a special Gummi Ship. The motorcycle is in turn named after Fenrir, a wolf summon which has appeared in multiple Final Fantasy games, in keeping with Cloud's wolf-motif. Fenrir is the shortened name of the Norse god Fenrisulfr.

Gameplay
Despite the passive ability of Negative Combo, the Fenrir Keyblade makes it up for its high attack power. It is also the strongest Keyblade available; its strength rating even surpassing that of the Ultima Weapon.

Fenrir is the only equipment with the "Negative Combo" ability, and if used with Sora's learned "Negative Combo" equipped and all "Combo Plus" and "Air Combo Plus" abilities unequipped, Sora will exclusively use combo finishers. This makes it required for mini-games like Junk Sweep, Cargo Climb, and Phil's Training, which focus on the use of combo finishers. Furthermore, as bosses in Kingdom Hearts II cannot be defeated unless a combo finisher is successfully performed on them, the Fenrir is quite useful against bosses who tend to interrupt Sora's combos.

Other media
The Fenrir Keyblade is packaged with the Series 1 Play Arts Figures Valor Form figure.