The Armored Ventus Nightmare is the final boss of Kingdom Hearts 3D: Dream Drop Distance. It is a Nightmare Dream Eater that has possessed Ventus's Keyblade Armor, which Ven had summoned earlier to protect Sora from the darkness.
The Armored Ventus Nightmare is Sora clad in Ventus's Keyblade Armor, now black in coloration. The Nightmare Dream Eater insignia is emblazoned on the visor. The Nightmare wields Sora's Kingdom Key, which is similarly tinted black.
Master Xehanort attempts to transform Sora into one of the thirteen Xehanorts and infuses his heart with darkness. While Ventus's light is able to summon his armor to shield Sora's heart, the armor is quickly possessed by darkness.
With Sora unconscious, Riku is forced to dive into Sora's heart to save him. Upon arrival, the Nightmare emerges from the darkness and engages Riku in battle. Eventually, RIku is able to defeat the Nightmare and save Sora from within.
The Armored Ventus Nightmare mimics Ventus's fighting style, even wielding Sora's Keyblade in Ventus's reverse-grip style. It can perform quick and brutal combos reminiscent of Fever Pitch, cast a dark Aero spell to defend itself, fire four orbs of darkness that can home in on Riku, and leap into the air to fire unblockable orbs of darkness that crawl on the floor. It also has a penchant for melting into the ground like a Shadow Heartless. When its HP is at 1, it can execute a Shotlock-esque technique where it can rush Riku while cloaked in darkness.