Combined Keyblade

The Combined Keyblade is the Keyblade that Sora and Riku summon in the last of phase of Nightmare's End and Mirage Split, respectively, in Kingdom Hearts 3D: Dream Drop Distance. It also appears in Kingdom Hearts III to briefly fend off the Demon Tide.

Kingdom Hearts III
When Sora arrives at the End of Sea to aid Riku and Mickey in rescuing Aqua from the Realm of Darkness, Sora and Riku summon the Combined Keyblade to destroy a Demon Tower.

Design
The Combined Keyblade is made of two Keyblades that can merge into each other to become one single Keyblade.

Sora's half of the weapon consists of a simple, dark hilt with blue strips that form X's all over. The guard is incomplete, with a golden color scheme on the incomplete end and an initially teal scheme for the completed end, gradually becoming green. This half of the guard merges into the blade, which is an enormous, golden filigree reminiscent of the Ultima Weapon's. The blade forms one half of a heart at the tip. The teeth of the weapon consists of a stained-glass window pattern, bearing blue, teal, yellow, magenta, and orange colors. The Keychain consists of golden links, with the charm a silver heart with golden wings that gradually become teal.

Riku's half bears a similar style to Sora's half, but this version has a periwinkle scheme for the incomplete side of the guard and a pink scheme for the completed side, gradually becoming periwinkle. The blade initially has a teal color scheme that merges into black, with the teeth bearing blue, teal, and violet colors. The Keychain's links are silver, and the charm's wings are initially black, but merge into magenta.

When both Keyblades are merged, the incomplete sides of the guards are absent. At the center of the merged blades is a golden rod that is grey at the base with a Hidden Mickey, and merges with the hearts at the tip. A the very top is a golden crown resembling the one on Sora's necklace. The Keychain is a green string with a paopu fruit as the charm.