Armored Ventus Nightmare

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

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

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

Trivia

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