The Armored Ventus Nightmare is the final boss in Kingdom Hearts 3D: Dream Drop Distance.
After the dream that Sora was forced into by the Anti Black Coat Nightmare, the latent darkness within his heart began to overwhelm it because he delved too far into his dreams and entered a sleep which he may never wake up from, allowing a Nightmare to take control of him.
Unlike Riku, whose clothes and heart had grown an immunity to the darkness's effects, Sora was still vulnerable to the darkness, something that Young Xehanort pointed out to him as he fell asleep. In order to protect Sora's heart from the darkness gushing in, Ventus's heart intervened and gave Sora his Keyblade Armor.
After Master Xehanort is revived and the true Organization XIII leaves the Realm of Sleep to finish their scheme, Riku, Mickey and Lea return to the Realm of Light with Sora's comatose body, and Riku enters Sora's heart in order to save him. When he reaches Sora's station, he is met with Sora in Ventus' armor controlled by the Nightmare, who is prepared to fight him. Riku has no choice other than to engage Sora to save him.
After Riku defeats Sora, the Armored Ventus Nightmare disappears, leaving an unconscious Sora behind.
The Armored Ventus Nightmare is composed entirely out of Ventus's armor, however the only difference is that is has now a darker black hue over the entire armor. It has a Nightmare Dream Eater symbol on the front of its helmet. It wields a black version of the Kingdom Key. Like Ventus, the Nightmare Armor Ventus wields its Keyblade with a reverse grip.
The Armored Ventus Nightmare is capable of using Ventus's moveset. It has amazing speed and each hit packs quite a punch, also, its combos are similar to Ventus's Fever Pitch Command Style.