Vanitas Remnant

The Vanitas's Lingering Spirit is an Unversed that serves as a secret boss in Kingdom Hearts Birth by Sleep and Kingdom Hearts Birth by Sleep Final Mix. It can be fought in the Badlands area of the Keyblade Graveyard after the player clears the Final Episode. True to its name, it is a physical manifestation of the remnants of Vanitas's thoughts, feelings, and will.

Defeating the Vanitas's Lingering Spirit in the Japanese version of Kingdom Hearts Birth by Sleep earns the player a Secret Gem. In the North American, PAL, and Final Mix versions of the game, defeating this boss unlocks the Void Gear and allows the Unknown to be challenged.

Story
Terra, Ventus, and Aqua return on separate occasions to the Badlands, where they find a mysterious sphere of dark energy hovering in front of a nearby rock formation. The Keyblade wielders accept the challenge the energy sphere offers, and the Vanitas Remnant takes shape before them, just like when the real Vanitas did when he was born. The Unversed attacks, and after its defeat, it disappears back into the darkness.

Design
The Vanitas Remnant wears a smooth, black helmet that has an Unversed emblem on it. The boss also wears a black and white bodysuit, white boots with black soles, and a white half-skirt that has torn, black tips and is held in place by three grey straps. In other words, its appearance is a black-and-white version of the real Vanitas. It also wields a monochrome colored version of Vanitas' Void Gear.

The portal from which the Vanitas Remnant emerges resembles those of the Absent Silhouettes that appear in Kingdom Hearts II Final Mix. It is purple in coloration, and fragments of black, rocklike material float around it. The symbol that appears in the portal's center resembles the Keychain of the Void Gear Keyblade.

Attacks

 * Continuous Slash (連続斬り): The Vanitas Remnant dashes and then slashes at its opponent. It then performs an upward somersault slash that releases a crescent-shaped wave of dark energy that homes in on its target and inflicts Confuse if it makes contact.
 * Warp (ワープ斬り下ろし): The Vanitas Remnant teleports above its opponent and strikes downward while casting Blizzaga.
 * Dark Firaga (ダークファイガ): The Vanitas Remnant launches a fireball at the opponent that soon divides into three smaller, homing fireballs.
 * Dark Thundaga (ダークサンダガ): The Vanitas Remnant strikes downward while casting Thundaga.
 * Shadow Dive (シャドウダイブ): The Vanitas Remnant dives into the ground and homes in on its opponent. Once it is within range, the boss reemerges as several fireballs rain down.
 * X-Discharge (Xディスチャージ): The Vanitas Remnant powers up its Keyblade and slashes at its opponent. It then releases an X-shaped wave of energy that homes in on its target.
 * Dark Splicer (ダークスプライサー): The Vanitas Remnant slashes at its opponent while teleporting. The length of this attack increases as the Vanitas Remnant's HP is depleted.
 * Dark Spiral (ダークスパイラル): The Vanitas Remnant dashes through the air at high speeds while wrapped in dark energy. This attack is used more often as the Vanitas Remnant's HP is depleted.
 * Curaga (ケアルガ): The Vanitas Remnant restores its HP. This spell is only cast if the opponent casts it first.
 * Spiraling Slash (回転突進斬り): The Vanitas Remnant impales its opponent while spinning.
 * Dark Fang (ダークファング): The Vanitas Remnant wraps the battlefield in darkness, dashes quickly, and places a row of dark crystals on either side of its opponent. These crystals rush at the opponent and inflict Blind on contact.
 * Clone Burst (クローンバースト): The Vanitas Remnant encases itself in a sphere of impenetrable, dark energy and launches several dark clones itself at the opponent before rushing forward with an attack of its own that inflicts Blind if it makes contact.
 * Dark Cannon (ダークキャノン): The Vanitas Remnant uses a Shotlock to fire a beam of blue energy from the tip of its Keyblade at the opponent.
 * Afterimage: If the Vanitas Remnant is caught in its opponent's combo, it teleports above its foe to retaliate.

Strategy
Terra, Ventus, and Aqua cannot use D-Links against the Vanitas Remnant. However, they still have access to Command Styles and Shotlocks. While the Vanitas Remnant will avoid most of the damage Shotlocks cause, the brief invulnerability these techniques grant makes them useful for enduring the boss's attacks. For maximum efficiency, the protagonists' equipped Shotlocks should be at their highest levels.

Depending on the approach to this battle the player wishes to take, their Keyblade of choice will vary. Keyblades with a high Strength stat are best used if one intends to fight the Vanitas Remnant using Aerial Slam. Magic-oriented Keyblades, meanwhile, are recommended if one plans to use Tornado or Seeker Mine.

Terra, Ventus, and Aqua should rely on the most basic forms of their respective dodging techniques when fighting the Vanitas Remnant, as their more offensive versions do not grant the same windows of invincibility. The protagonists should also use Potions or techniques such as Heal Strike, Renewal Block, and Renewal Barrier to recover HP, for Cure and Friend Cure spells allow the boss to also rejuvenate itself.

Terra
To compensate for his lack of speed and poor dodging ability, Terra should only use the fastest of attacks when facing the Vanitas Remnant. It is also recommended that he enter the battle against this foe with two sets of Potions, a high-level version of Mine Square or Mine Shield, all three available HP Boosts, and the Second Chance and Once More abilities equipped. To deal as much damage to the Vanitas Remnant as possible, Terra should use the Chaos Ripper Keyblade, as well as the Demolition Finish command.

When dealing with the Vanitas Remnant's Clone Burst attack, Terra should use Slide to avoid taking damage. He should not use Sonic Impact, as this technique lacks Slide's temporary invincibility. Terra can also use Keyblade strikes and fast-paced, long-range attacks like Thunder Surge to delay Clone Burst's execution. When the Vanitas Remnant uses Dark Fang, it is recommended that Terra use Slide to quickly reach the boss and then use Mine Shield or Mine Square; it is likely the Vanitas Remnant will walk into the mines and take damage in its attempt to continue attacking. If the Vanitas Remnant uses Dark Cannon, Terra can use Ars Solum to deal heavy damage. Alternatively, he can consume a Vanilla Glitz to gain early access to the Critical Impact Command Style; this will greatly increase the damage of his standard attacks, which can be used until the boss's Shotlock ends.

Ventus
When fighting the Vanitas Remnant, Ventus should use Dodge Roll to avoid taking damage. He can use Superglide to quickly dodge the boss's ranged attacks. It is recommended that Ventus have at least two sets of Potions equipped during this battle, as well as the Second Chance and Once More abilities. Tornado and Mine Square should be his main source of offense, and he should use Renewal Block to defend against the Vanitas Remnant while recovering much-needed HP.

To avoid Dark Fang, Ventus should use Dodge Roll. The temporary invincibility the technique grants him will prevent him from being inflicted with Blind. Ventus's Stratosphere Finish command also bestows brief invulnerability; it should be used in place of Command Styles. Ventus's Tornado spell is most effective at the conclusion of the Vanitas Remnant's Dark Thundaga, Clone Burst, and X-Discharge attacks.

Aqua
When Aqua faces the Vanitas Remnant, she should have Seeker Mine and all three available HP Boosts equipped. Her Keyblade of choice should either be the Stormfall or Ultima Weapon Keyblade, as both are proficient in Strength and Magic. To avoid the Vanitas Remnant's attacks, Aqua should chain multiple Cartwheels together.

Strategy 1
In addition to Seeker Mine, Aqua should have three sets of Potions and four sets of Fabracadabras equipped. After three quarters of the Vanitas Remnant's HP has been depleted, it is recommended that Aqua start using Fabracadabras to gain early access to the Spellweaver Command Style, which she can use until the boss is defeated. While not particularly powerful, Spellweaver grants Aqua invulnerability, has great range, and can hit multiple times.

Strategy 2
A strategy that involves the consumption of fewer items relies on a combination of Seeker Mine and Teleport Spike as its main source of offense. Aqua should use this command until three quarters of the Vanitas Remnant's HP has been depleted. She should then use consecutive Counter Blasts to fill her Command Gauge until Teleport Spike becomes available. It is recommended that Aqua utilize this Finish command until the Vanitas Remnant is defeated to gain temporary invulnerability and the ability to strike multiple times.

Terra, Ventus, and Aqua
A glitch in the Vanitas Remnant's A.I. allows for an easy victory against it. Simply lure the Vanitas Remnant to the large rock formation in the corner of the battlefield and retreat to the rock's opposite side. The Vanitas Remnant will be left unable to attack. Terra, Ventus, and Aqua can effortlessly defeat the boss with a Command Deck comprised entirely of Strike Raid commands.