Lingering Will

The Lingering Sentiment (留まりし思念) is an unlockable secret boss featured in Kingdom Hearts II Final Mix and a briefly playable character at the climax of Terra's story in Kingdom Hearts Birth by Sleep. It is merely the lost thoughts and feelings of Keyblade wielder Terra residing within the man's discarded armour, the emotions and armor lost to him during the final battle with Master Xehanort.

Kingdom Hearts II
A man connected to the portal﻿ which appeared at Disney Castle.

The armor covering his body can master the Keyblade's power much more than Sora.

Kingdom Hearts Birth by Sleep
After losing his first battle with Terra, Master Xehanort witnessed the creation of the X-Blade along with the young Keyblade wielder. Seeking to use the man's darkness as a younger, more powerful weapon as he ventured further into the mysteries of the Keyblade War, Master Xehanort then proceeded to unlock his heart. Terra attempted to shield himself with his armor, this proving to no avail, the man becoming a younger incarnation of Master Xehanort. Just as the new Xehanort began to venture away from the place of Terra's fall, he soon found himself trapped within a force field, turning to find Terra's armor standing reassembled before him, Terra's mind having found residence within it. Angered by Terra's defiance, he then engaged the Lingering Sentiment in a long, fierce battle.

In the end, the Lingering Sentiment emerged victorious, knocking Xehanort unconscious. The armored figure then thrust its Keyblade into the ground, kneeling down in a similar fashion to that of its Kingdom Hearts II Final Mix incarnation upon its meeting with Sora eleven years later. Soon after, Xehanort was consumed in an immense sphere of light, the result of Aqua and Ventus shattering the X-Blade during the process of defeating Vanitas. Kingdom Hearts then disappeared from the sky above, leaving the Lingering Sentiment to remain alone in the Keyblade Graveyard, promising to Aqua and Ven that someday, somehow, it would put an end to the conflict.

Kingdom Hearts II Final Mix
After the defeat of Xemnas, a portal to the Keyblade Graveyard appeared in Disney Castle. Sora, Donald, and Goofy proceeded to enter the portal and find the Lingering Sentiment, which at first mentioned Aqua and Ventus. It then mistook Sora as "the one he had chosen", wondering if Sora was Xehanort before finally attacking him. Sora managed to defeat the Lingering Sentiment after an intense battle, and the Lingering Sentiment respectfully acknowledging Sora as a true Keyblade master. If Sora returned for another match, the Sentiment would accept its defeat, but not before stating that it had nothing left to give him and that all it had left is its hatred for Xehanort.

In the game, the Sentiment speaks to Sora through enigmatic sounds, much like Xemnas did in Kingdom Hearts Final Mix, yet Sora appears to be capable of understanding it, demonstrated by when he, Donald and Goofy immediately take fighting stances when the Sentiment mentions Xehanort.

Abilities
It, like Kingdom Hearts II Final Mix ' s other secret bosses, is difficult to defeat; its most basic moves are attacking with its Keyblade Gaia Bane, using a combo attack almost identical to Sora's, though it instead turns its Keyblade into a drill-like object for the forward thrust combo finisher, and can fly at very high speeds. Its main abilities are transforming its Keyblade into various attacking forms. It can turn it into a whip that does less damage than the blade form, but its greater speed and range makes up for it. In addition, the Lingering Sentiment's Keyblade can also turn into a massive cannon which is larger than the enemy itself, that fires out a large, very powerful ball of energy. Sora, however, can deflect this back to the Lingering Sentiment, which leaves it very vulnerable. The Lingering Sentiment can also transform its Keyblade into a jet ski-like object that lets it fly extremely fast, and a cog-like object that spins around so fast that if Sora gets hit by it once, then the rest of the hits will also hit Sora.

The Lingering Sentiment can also conjure a "ritual" like attack; in this attack, the Lingering Sentiment enters a berserker-like condition, similar to Saïx's Berserk technique. Its arm gauntlets and helmet will emit a bright red aura; he then can split his Keyblade into two weapons. This, when added with its combos, makes it extremely lethal. In this attack, the Lingering Sentiment is only vulnerable after completing an attack or after deflecting the cannon-formed Keyblade's shot back at him. Any other time that you attack him will be null.

In addition to its Keyblade, the Lingering Sentiment has other abilities as well. It can also create an unusual looking seal that either creates an orange or blue orb. An orange orb causes Sora to be unable to attack and a blue orb prevents Sora from using magic or items. It can also use some magic; for example, when the Lingering Sentiment is doing a Sonic Blade-like attack while low on HP or attacking with its jet ski-formed Keyblade, it sometimes will use Blizzard. Also, when it turns its Keyblade into a jet-ski like object and rides it and if you are too far from it. It will sometimes use Graviga that does some damage, and will pull Sora into its path. The Lingering Sentiment can also conjure drone-like objects which fire plasma at Sora and his party. A particularly deadly attack is trapping Sora in a triangle of objects that drain his heath at a very fast rate, similar to an attack used by Xemnas, but much more powerful; only a "Break Free" command on Sora's command list can save him from it. If the player chooses the wrong command while he is trapped, then Sora will immediately die, even with Once More and Second Chance equipped. Interestingly, when it strikes Sora with its Keyblade(s), most of its combos resemble Sora's combos, most notably the Valor Form and Final Form combos.

When playing as the Lingering Sentiment during the final battle with Xehanort at the Keyblade Graveyard in Kingdom Hearts Birth by Sleep, it loses Terra's ability to use D-Links; the D-Link Guage shall be empty with no way to refill it. Retaining Terra's immense power, the Lingering Sentiment has access to any abilities equipped before the battle begins, including all Shoot Locks, attacks, and spells. While Terra was able to wield whichever Keyblade the player equipped, the Lingering Sentiment's weapon is preset as the Gaia Bane.

Weapon
When the new Xehanort was born, he sacrificed both Terra's armor and the Gaia Bane Keyblade for Master Xehanort's old weapon. Because Terra's soul resided within the Lingering Sentiment, it was able to wield the Gaia Bane to conquer Xehanort. The Gaia Bane would then remain with the Lingering Sentiment in its solitude at the Keyblade Graveyard; the animated armor would use the Keyblade a second time to battle Sora eleven years later.

The Lingering Sentiment is a very capable Keyblade wielder, able to morph the Gaia Bane into several different forms. It shares Terra's ability to Keyblade Ride, using what was once a form of transportation for the hero as an offensive technique. Other forms the Gaia Bane may take through the Lingering Sentiment's influence include a chain whip, the massive cannon-like form used in Terra's Ultima Cannon Shoot Lock, a drilling gauntlet, and a harken-like weapon. Save for the Keyblade Ride and Ultima Cannon, these forms were each unique to the Gaia Bane when wielded by the Lingering Sentiment. The armor also holds the weapon in a different fashion in Kingdom Hearts II Final Mix than in Kingdom Hearts Birth by Sleep, the latter's version identical to that of Terra.

Personality
As the Lingering Sentiment is truly an inanimate object, it cannot feel or possess a personality of its own. Since it was brought to life by Terra's discarded thoughts and emotions, however, it is able to "feel" a strong hatred towards Xehanort, as well as a close connection and devotion to Aqua and Ventus.

Appearance
The Lingering Sentiment is an animated suit of armor. The helmet is mostly gold, excpet for the visor, which is black, and it sports two, red prongs, one on either side of the helmet, that point straight up. The arms, legs, and ribs of the armor is black had have orange patterns decorating them. Its knee guards, gauntlets, breast plate, and armored boots are gold, and there are other, smaller pieces of gold armor on its legs. It wears black shoulder pauldrons with gold edges. The front of the armor on the Lingering Sentiment's torso is red, as are small pieces of armor on its lower legs and gauntlets. It also wears gold anklets with red spikes on the back that curve upward sharply.

In Kingdom Hearts II Final Mix, The Lingering Sentiment's armor seems to be much darker in coloration, either because of the lack of light in the Keyblade Graveyard, or that the long period of time it spent there simply faded the armor. It also wears a cape that is gold on the outside and black on the inside, which was never part of the armor in Kingdom Hearts Birth by Sleep due to difficulty including it in the render. While the Lingering Sentiment appeared as a secret boss while Kingdom Hearts Birth by Sleep was still in development, this feature was removed to prevent lagging issues during Kingdom Hearts Birth by Sleep's gameplay. As it is Terra's discarded armor, the Lingering Sentiment uses his main Keyblade, Gaia Bane, in all of its appearances.

In both appearances, the Lingering Sentiment is somehow able to communicate mentally. However, it lacks a physical voice, being totally silent in battle.

Quotes

 * "Aqua... Ven... Keyblade... Who are you? I can feel it - we have met before. But when... No... it isn't you... It isn't you that I have chosen. Why isn't it him? Xe...ha...nort... Is that you? Xeha...nort... Xehanort!"
 * "I see. Your strength is... What I sensed in you is..."
 * "Xe....ha.....nort..... Where are you?"

Trivia

 * Upon its creation at the end of Kingdom Hearts Birth by Sleep, the Lingering Sentiment doesn't wear a cape, but when Sora faces it ten years later, it does. This change was made to avoid lagging issues in Kingdom Hearts Birth by Sleep.
 * Certain changes are noticeable between The Lingering Sentiment in its Kingdom Hearts II Final Mix and Kingdom Hearts Birth by Sleep incarnations, such as its Keyblade being more than a foot longer and its armor being darker.
 * The Lingering Sentiment is the second superboss to gain a playable role, succeeding Xemnas.
 * The Sentiment's first quote, about Sora not being "the one he chose" refers to when Terra met Riku on Destiny Islands as a child and saw him to be his successor.
 * The Lingering Sentiment is the only superboss who is not evil. However, the exact role of the Vanitas Sentiment remains to be seen.
 * Storywise, after Xemnas' destruction, Sora is sent to the Dark Margin and almost immediately afterwards is sent back to Destiny Islands. However, in the game, the portal to the Keyblade Graveyard only appears after the defeat of Xemnas, leaving the canonicity of the Lingering Sentiment's encounter and subsequent battle with Sora questionable.