Aubade

The Aubade (オウバードロード) is a form of the Kingdom Key that appears in Kingdom Hearts 358/2 Days. It is one of two unique weapons that Roxas and Xion can wield. What makes the Aubade special is that it turns into a grand Keyblade with its Gear, yet that Gear is one that usually creates a Joke Weapon.

The Kingdom Key is changed into the Aubade when the Mystery Gear is equipped.