Fatal Crest

The Fatal Crest (フェイタルクレスト) is a Keyblade obtainable in Kingdom Hearts II by completing the Goddess of Fate Cup.

Design
The neck of the Keyblade appears to be that of a skeletal dragon, of which still has life in some of it. Unlike most Keyblades, this Keyblade features a curved neck. The handle is the landmark that defines The Underworld and is seen on the river Styx. The token is the Hades Cup.

In Combat
It gives the largest magic bonus of any Keyblade, making it good for usage with Wisdom Form. Its usefulness for this is undercut in Kingdom Hearts II Final Mix by the Winner's Proof Keyblade, boasting slightly more powerful stats.

Other media
The Valor Form edition of the Play Arts Figures comes packaged with Fatal Crest as one of the Keyblades. Ironically, Fatal Crest is best used for its magical capabilities--and since Berserk Charge requires a complete loss of MP, Fatal Crest is essentially useless for Valor Form as the use of magic is sealed during this form.