When Riku travels to Sora'sDive 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.
Armored Ventus Nightmare is Ventus'sKeyblade 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, with a reverse grip.
Kingdom Hearts 3D: Dream Drop Distance marks the first time Sora himself appears as a boss.