Lingering Will

Lingering Will is a collection of thoughts and desires of the Keyblade wielder Terra. It took control over Terra's discarded Keyblade Armor after his body was possessed by Xehanort. Along with Terra's heart within the Dark Figure and its master Terra-Xehanort, it represents Terra's continued consciousness even after his possession and takeover at the hands of Xehanort. Lingering Will is playable for a short time at the end of Terra's scenario in Kingdom Hearts Birth by Sleep; it made its debut appearance in the  series as a secret boss in Kingdom Hearts II Final Mix.

Development
The Lingering Will's voice in Kingdom Hearts II Final Mix is represented by metallic grinding, similar to Xemnas in Kingdom Hearts Final Mix.

In Kingdom Hearts HD 2.5 ReMIX version of Kingdom Hearts Birth by Sleep Final Mix, Lingering Will sprouts a cape upon victory; this is to prevent continuity errors with its appearance in Kingdom Hearts II Final Mix, where it has a cape.

Kingdom Hearts Birth by Sleep
When Master Xehanort extracts his heart in an attempt to possess Terra, Terra summons his Keyblade Armor in a desperate attempt to defend himself, but fails due to his darkness, allowing Xehanort's heart to take over regardless. The newly born Terra-Xehanort discards the Keyblade Armor and walks off in triumph, only to become trapped in Will's Cage. Terra-Xehanort turns in shock to see Terra's Keyblade Armor reassembled and standing before him; Terra's rage towards Xehanort and his desire to protect his friends has given life to his discarded armor. Determined to stop Master Xehanort at all costs and get back its body, Terra's "lingering will" challenges Terra-Xehanort to a battle. Angered by Terra's continued resistance, Terra-Xehanort readily engages it.

In the end, Lingering Will is victorious in battle, but although Terra-Xehanort is knocked unconscious, it fails to expel Xehanort from Terra's body. The armored figure plunges its Ends of the Earth into the ground and slumps down, as Terra-Xehanort is consumed by the light storm created by the destruction of the χ-blade via Aqua and Ventus. The clouds that have masked the Keyblade Graveyard in darkness cover Kingdom Hearts in the sky above, and Lingering Will is left alone. It silently promises Aqua and Ventus that someday, it will set things right.

Kingdom Hearts II
Eleven years later, a portal to the Badlands appears in Disney Castle. Sora, Donald, and Goofy enter it and find themselves standing before the kneeling Lingering Will. The animated Keyblade Armor mentions Aqua and Ventus before sensing Sora's Keyblade, and it mistakes Sora for the one it had chosen, Riku. Realizing its mistake, Lingering Will asks why Sora is not him; it then wonders if Sora is Xehanort, slowly pronouncing the latter's name. Determined to fulfill the promise it made long ago to avenge itself and its friends, Lingering Will rises to its feet and picks up its Keyblade. Sora and friends draw their weapons in preparation for the upcoming fight, and after an intense struggle, they eventually defeat their silent attacker. Upon its loss, Lingering Will senses Ventus's presence within Sora and kneels back down. If Sora returns to battle Lingering Will after this, it accepts his challenge, but it states that it has nothing left to give the young Keyblade wielder other than its contempt for Xehanort.

Kingdom Hearts III
In The Final World, Sora encounters Naminé's heart, who tells him she found a connection to Terra's "strong will", and tries to make contact with it.

After returning to the point in time before their defeat in the Keyblade Graveyard, the Guardians of Light are once again confronted by Terra-Xehanort. This time, however, the Lingering Will arrives and fights him, leading both of them away from the group.

During their battle, Terra-Xehanort catches the Lingering Will off guard with the Dark Figure. As the Dark Figure prepares to crush the Lingering Will's head, Sora's future self arrives and fends them off. Sora is caught by the Dark Figure, but before Terra-Xehanort can finish Sora off, the Lingering Will intercepts the attack and is destroyed, sacrificing itself to save Sora.

Kingdom Hearts Re:coded
In the opening credits of Kingdom Hearts Re:coded, the Lingering Will is seen kneeling down after the defeat of Terra-Xehanort.

Design
The Lingering Will is an animated suit of Keyblade Armor. Its helmet is mostly gold, except for its black visor, and it sports two red prongs (one on either side of the helmet) that point upwards. The arms, legs, and ribs of the Keyblade Armor are black and have orange patterns decorating them. Its knee guards, gauntlets, breastplate, and armored boots are gold, and there are other, smaller pieces of gold armor on its legs. The Lingering Will wears black pauldrons with gold edges. The front of the armor on its torso is red, as are small pieces of armor on its lower legs and gauntlets. Lingering Will also wears gold anklets with red spikes on the back that curve upward sharply.

In Kingdom Hearts II Final Mix and Kingdom Hearts III, Lingering Will's armor is much darker in coloration. It also wears a cape that is gold on the outside and dark blue on the inside. This cape was removed from Lingering Will's design in Kingdom Hearts Birth by Sleep in order to avoid framerate issues. However, it was reintegrated in the cutscene after the Lingering Will defeated Terra-Xehanort at the end of Terra's scenario in Kingdom Hearts HD 2.5 ReMIX.

Personality
As the Lingering Will is not truly a living being, it cannot feel or possess a personality of its own. It was brought to life by the thoughts and emotions that Terra left behind when Xehanort took his body, so while it feels some connection to Aqua, Ventus, and Riku, its driving focus is to revenge itself on Xehanort. It is able to speak, but due to its single-minded purpose its words are terse, dispassionate, and to-the-point. Despite this, it does feel a desire to protect Aqua and Ventus to the point it is willing to destroy its former body as long as Xehanort's heart inhabits it as it perceives Terra-Xehanort as a threat to Aqua and Ventus.

Despite being physically separate from Terra's heart and body, the Lingering Will carries Terra's continued consciousness, as shown when in-game tips refer to Terra-Xehanort's body as "[its] body" and how it refers to Riku as the one "it" chose. Before the Dark Figure's reveal as a vessel for Terra's heart, Sora and the other protagonists believe the Lingering Will to be all that remains of Terra's own thoughts and desires, and refer to it by the name of its original self.

Fighting style
Lingering Will, like Kingdom Hearts II Final Mix ' s other secret bosses, is difficult to defeat. Its most basic move is a three-hit Keyblade combo almost identical to Sora's. The difference, however, is that the Lingering Will can Formchange its Keyblade into a drill-like object for the forward thrust that serves as the combo finisher. This is just one of many Formchanges the Lingering Will's Keyblade assumes during the battle against it; another Formchange it can assume is a whip that deals less damage than its blade form in exchange for greater speed and range. Lingering Will can also fly at high speeds and use Terra's Ultima Cannon Shotlock. Unlike when Terra's Shotlock is used, however, the resulting blast can be deflected via a well-timed Guard to damage the Lingering Will instead. This leaves it vulnerable to further attacks. The Lingering Will can also Formchange its Keyblade into a Keyblade Glider or cog-like object to perform extremely quick attacks.

Lingering Will can also create a large rune on the ground below it as lightning rains down from above. At this point, the Lingering Will enters a berserk state that causes its arm gauntlets and helmet to emit a bright red aura. The Lingering Will gains the ability to split its Keyblade into two, making its combos extremely lethal. After the first two stages of the Lingering Will's rapid combo have been evaded, the last few attacks can be blocked by Sora via a well-timed Guard.

Lingering Will is also quite skilled at wielding magic. It can create an unusual-looking seal that either creates an orange or blue orb. An orange orb prevents Sora from attacking, while a blue orb blocks the use of magic and items. The Lingering Will may sometimes use Blizzaga while executing a Sonic Blade-like attack at low HP or when riding its Keyblade Glider. It will also use Magnega while atop its Keyblade Glider if Sora is too far from it. The Lingering Will can conjure drone-like objects which fire lasers at Sora, Donald, and Goofy, as well. It may sometimes transform its Keyblade into a bow and fire arrows that trap Sora in a triangular-shaped seal that drains his health at a fast rate; only a "Release" command can save Sora from it. If the player chooses the wrong command while Sora is trapped, Sora will expire regardless of Once More or Second Chance, although Peter Pan's Auto-Life ability will allow him to continue fighting.

When playing as Lingering Will during the final battle with Terra-Xehanort at the Keyblade Graveyard in Kingdom Hearts Birth by Sleep, it loses Terra's ability to use D-Links; the D-Link Gauge is empty and unable to be refilled for the entire battle. The Lingering Will does, however, retain Terra's immense power and has access to any abilities that were equipped to him before the battle begins. Lingering Will also can use Terra's equipped Shotlock and all commands that were placed in his Command Deck. While Terra's Keyblade was able to be equipped with any Keychain of the player's choosing, Lingering Will's Keyblade defaults to the Ends of the Earth.

Weapon
As Terra's possessed Keyblade Armor, Lingering Will wields his former Keyblade, the Ends of the Earth. When Terra-Xehanort is created, he forsakes the Ends of the Earth in favor of No Name. Because Terra's will finds residence within his Keyblade Armor, Lingering Will picks up the Ends of the Earth upon its creation and uses it to conquer its possessed body. The Ends of the Earth remains with Lingering Will during its solitude at the Keyblade Graveyard; the animated Keyblade Armor uses the weapon a second time to battle Sora eleven years after its struggle against Terra-Xehanort.

Lingering Will can Formchange the Ends of the Earth into a myriad of weapons, including Terra's Keyblade Glider, the cannon-like form used in Terra's Ultima Cannon Shotlock, a chain whip, a drilling gauntlet, and a harken-like weapon. Save for the Keyblade Glider and Ultima Cannon, these forms are all unique to the Ends of the Earth when it is wielded by Lingering Will. While Lingering Will's battle stance with the Ends of the Earth is identical to Terra's in Kingdom Hearts Birth by Sleep, it adopts a different stance in Kingdom Hearts II Final Mix.