Fenrir

 The Fenrir is a Keychain for Sora's and the Player's Keyblades that appears in Kingdom Hearts II and Kingdom Hearts Unchained χ. The Fenrir is also one of the types of Keyblades left at the Keyblade Graveyard.

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 in the middle of their duel, Tifa thanks Sora for his help and gives him the Fenrir Keychain.

Design
The Fenrir, unlike all other Keyblades, takes on the appearance of a key, and is based upon Cloud's Fusion Swords.

In Kingdom Hearts II, the Fenrir has a red handle similar to that of the Fusion Swords and a dark grey guard. Two rods jut out of the top of the guard, similar to the Fusion Swords' racks on Cloud's motorcycle from Final Fantasy VII: Advent Children. The blade is a pin tumbler lock key's shaft, with the base of the blade bearing bandages similar to those on Cloud's Buster and Fusion Swords in Kingdom Hearts. The Keychain is inspired by Cloud's Fenrir pendant from his Advent Children outfit.

In Kingdom Hearts Unchained χ, the Fenrir's appearance differs depending on its upgrades. The basic Fenrir has more of a bronze appearance, with a green or a rusted bronze handle. The rods on the guard are smaller, and the blade is not only smaller and duller, but is covered in bandages from the tip to the base. The Keychain is a dull bronze.

The first upgrade resembles its Kingdom Hearts II iteration, albeit with a lighter color scheme. The second upgrade, however, bears a strong resemblance to Cloud's motorcycle. The guard is a dark grey, with some golden highlights on the sides. There are two rods on each side of the guard, bearing more of a resemblance to the Fusion Swords' holsters. The blade has a grey highlight at the base, and is dark grey, bearing two pointed edges at the tip. The Keychain has a golden color scheme.

The Fenrir is named after Cloud's motorcycle 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 wolf-god. In the Dissidia series, Cloud also gains his own version of the Fenrir as one of his weapons.

Gameplay
In Kingdom Hearts II, despite the passive ability of Negative Combo, the Fenrir Keyblade makes up for it with its high attack power. It is also the strongest Keyblade available, its strength even surpassing that of the Ultima Weapon.

The Fenrir is the only piece of equipment with the Negative Combo ability; in combination with the Negative Combo that Sora learns and a lack of equipped Combo Plus and Air Combo Plus abilities, Sora can attack with only combo finishers. This makes it essential for high scores in 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.