No Heart

No Heart (ノー・ハート) is a boss exclusive to Kingdom Hearts Birth by Sleep Final Mix that appears in the Mirage Arena. It is fought in the "Machinations unto Darkness" Arena Mission. During the battle, it sits on a throne in the Throne Room of the Land of Departure and occasionally stands up to fight directly, wielding Master Xehanort's Keyblade.

Design
No Heart wears a suit of Keyblade Armor branded with a single Nobody emblem centered on the torso, Nobody emblem-esque thorns protruding from its greaves, and Nobody emblem-esque thorns wrapping around its boots. Its crown and shoulder pad are gold, while the rest of the armor is colored in light shades of blue and silver. It has two silver belts on its waist and what seem to be white feathers on its right shoulder in place of a spiked pauldron. Several cords criss-cross in front of its torso, connecting to massive, oblong pieces of armor worn on each arm. No Heart's faceplate is beak-like in structure and it wears clawed gauntlets. It also wears black pants underneath the armor. Odd, sleeve-like additives hang from the ends of the armor on No Heart's arms. It wields Master Xehanort's Keyblade in battle.

No Heart bears a striking resemblance to Xemnas's Armored Controller form.

Like "Another", "No Heart" is an anagram of Xehanort without the X in the name.

Strategy
No Heart is one of the game's strongest secret bosses, rivaling the Unknown. Its attacks are strong and can deal heavy damage. In terms of preparation, the player should be at a high level, have a strong Keyblade, max HP, and lots of Cure and Potion commands.

In the first phase of the battle, No Heart remains stationary, protected by a large barrier of dark energy. To disable the barrier, the player must attack No Heart's Keyblade, which is constantly floating around. In terms of offense, No Heart will summon a swarm of flying Keyblades from the Keyblade Graveyard to attack the player. The Keyblades do not have a lot of HP and are vulnerable to any attack. After dispelling the barrier, the fight becomes more serious as No Heart rises from the throne, removes its cape and challenges the player directly.

This is the harder phase of the battle. The boss possesses an arsenal of potent dark-based attacks which can deal large, and possibly fatal damage. No Heart mainly uses Sonic Impact, darting around the arena to attack the player. The boss can utilize Dark Volley to strike from a distance, as well as summon flying Keyblades to attack. The boss can create waves of dark energy by swinging its Keyblade. It may also leap into the air and slam the ground to create a large shockwave. No Heart can use Reversal to maneuver around the player to unleash more Keyblade strikes, and may teleport to avoid attacks. No Heart also can create large pools of dark energy. The armor can also alter the shape of its Keyblade for strong attacks such as turning it into a claw to grab players(circle button must be pressed repeatedly to break its grip), morphing it around its leg for powerful kicks, and turning it into a wing to fly. From the air, it will either shoot more dark energy blasts, or use its most powerful attack: A large explosion of dark energy.

The player's reward for defeating No Heart is the Crown Unlimit Keyblade.

Trivia

 * The music that plays during No Heart's battle is a remix of Forze Del Male and Darkness of the Unknown, battle themes for Ansem, Seeker of Darkness and Xemnas, respectively.