- “Aqua... Ven... One day, I will make this right.”
- ―Lingering Will's first words
The Lingering Will is the lost mind of the Keyblade wielder, Terra, residing within the man's discarded armor after his body is stolen by Master Xehanort. It is a briefly playable character at the end of Terra's scenario in Kingdom Hearts Birth by Sleep.
- "Your body submits, your heart succumbs.......so why does your mind resist!?"
- —Terra-Xehanort to the Lingering Will
After losing his first battle with Terra, Master Xehanort witnesses the creation of the χ-blade along with the young Keyblade wielder. Seeking to use the man's darkness as a younger, more powerful weapon as he ventures further into the mysteries of the Keyblade War, Master Xehanort proceeds to unlock his heart. Terra attempts to shield himself with his armor, but to no avail, and the man becomes a younger incarnation of Master Xehanort. Just as the new Terra-Xehanort begins to venture away from the place of Terra's fall, he soon finds himself trapped within a force field, turning to find Terra's armor kneeling, reassembled, before him, Terra's mind having found residence within it. Angered by Terra's defiance, Terra-Xehanort engages the Lingering Will in a long, fierce battle.
In the end, the Lingering Will emerges victorious, knocking Terra-Xehanort unconscious. The armored figure then thrusts its Keyblade into the ground, kneeling down. Soon after, Terra-Xehanort is then consumed by an immense sphere of light, the result of Aqua and Ventus destroying the χ-blade following Vanitas's own destruction. The clouds overhead then cover Kingdom Hearts, disappearing above, leaving the Lingering Will to remain alone in the Keyblade Graveyard, silently promising to Aqua and Ven that someday, it will set things right.
Eleven years later, a portal to the Badlands in the Keyblade Graveyard mysteriously appears in Disney Castle. Sora, Donald, and Goofy proceed to enter the portal and find the Lingering Will in the same position as it had been left in. It mentions Aqua, Ven, and the Keyblade. It then mistakes Sora as "the one he had chosen"; realizing its mistake, it asks why he isn't "him". Then it wonders if Sora is Xehanort, slowly pronouncing the latter's name, before finally rising up as it did once before to attack him. Sora manages to defeat the Lingering Will after an intense battle, and the Lingering Will merely kneels down again after this. If Sora returns for another match, the Will accepts its defeat, but not before stating that it has nothing left to give him and that all it has left is its hatred for Xehanort.
The scene of the Lingering Will kneeling down after defeating Terra-Xehanort is shown in the opening credits.
As the Lingering Will is not truly a living being, 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. The Lingering Will lastly possesses a familiarity with Sora (who is carrying Ventus' heart) and Riku (Terra's successor).