Hidden Dragon

The Hidden Dragon is a Keyblade available to Sora in Kingdom Hearts II and Kingdom Hearts: Re:Chain of Memories.

Kingdom Hearts: Re:Chain of Memories
Hidden Dragon can be obtained in the English version of Re: Chain of Memories when the player uses a Calm Bounty in Traverse Town. As for the Japanese version of Re: Chain of Memories, Hidden Dragon can be unlocked only after completing Kingdom Hearts II: Final Mix+. Whenever a treasure chest contains a Hidden Dragon card, it mentions explicitly "Kingdom Hearts II: Final Mix+ Completion Bonus".

Kingdom Hearts II
The Hidden Dragon is the third Keyblade available to Sora in Kingdom Hearts II, preceded by the Kingdom Key and the Star Seeker. It is physically weaker than either of the keyblades available at the time, but stronger in magic.

Acquisition
The Hidden Dragon is acquired after clearing the Land of Dragons for the first time. Once Shan-Yu has been defeated, saving the Emperor from capture, Mulan and Sora are commended for their service. Mulan receives a medal bearing the Emperor's crest, and Sora earns this keyblade.

Design
The Hidden Dragon keyblade is designed with an oriental dragon theme. The guard is similar to the color and shape of Mushu. Its blade is a burst of fire coming out of Mushus mouth, while it features the medal Mulan receives for saving the Emperor on the key chain.

Etymology
The name for this Keyblade is most likely based on the title of the Chinese story Crouching Tiger, Hidden Dragon. This is enforced due to the fact that it is obtained in The Land Of Dragons, which is based off of ancient China.