Armored Ventus Nightmare

Nightmare Armor Ventus is the final boss of Kingdom Hearts 3D: Dream Drop Distance.

Kingdom Hearts 3D: Dream Drop Distance
When Riku travels to Sora's Dive to the Heart, the Nightmare Armor appears out of the darkness and engages him in battle. Upon the Armor's defeat, the darkness covering Sora and his Keyblade cracks and fades away, leaving a comatose Sora behind as he falls into a pool of darkness.

Design
Nightmare Armor Ventus is Sora clad in Ventus's Keyblade Armor, which is now black in coloration. The Nightmare Dream Eater emblem is emblazoned on the visor. The boss wields Sora's Kingdom Key, which is also colored black, but with a reverse grip.

Trivia

 * Kingdom Hearts 3D: Dream Drop Distance marks the first time Sora himself appears as a boss.