Diamond Dust

The Diamond Dust (ダイヤモンドダスト) is a keychain which Sora obtains after defeating the Ice Titan in the Gold Match. This Keyblade is a Kingdom Hearts Final Mix exclusive along with the One Winged Angel Keyblade. It is also a weapon in Kingdom Hearts: Chain of Memories.

Appearance
The Keyblade appears to be made of ice, and the teeth and Keychain are snowflakes. It bears some resemblance to the Oathkeeper Keyblade.

Etymology
It shares the same name as one of Vexen's and Aqua's techniques, as well as the traditional technique of the summon Shiva from Final Fantasy.