Sora's Heartless

"Rage... Hatred... Glitches to feed my Darkness... And soon, Hearts to sate my hunger!"

- Sora's Heartless

Sora's Heartless is a recurring character in the Kingdom Hearts series. While it mostly appeared as a minor character, but doesn't pose as an antagonist throughout most of the Kingdom Hearts series, Sora's Heartless later appears as the main antagonist, as well as the penultimate boss in the videogames Kingdom Hearts coded and it's updated edition; Kingdom Hearts Re:coded. It is a Pureblood Heartless shaped in the namesake shadow of the heroic Keyblade wielder Sora, as well as being the one responsible for the Bug Blox that infected Jiminy Cricket's Journal when it was downloaded into data.

Appearance
The physical Sora's Heartless which appeared in Kingdom Hearts originally took the form of a Shadow, but when Kairi recognized him and hugged him close to her heart, the pure light of her heart restored Sora to his human form, but without his Nobody, Roxas, Sora was still incomplete.

The digital Heartless within the Journal, which appeared in Kingdom Hearts coded, strongly resembles the Darkside Heartless, as it has short legs, and long, muscular arms. It has a large heart shaped hole in its abdomen, which penetrates straight through from the front to the back. Sora's Heartless's head is covered in dozens of twisted, black tentacles and only its small yellow eyes - a trademark feature of any Heartless - are visible. Two small vestigial wings protrude from the creature's back. Sora's Heartless has black skin, but, unlike Darkside, its shoulders are adorned with yellow and red symbols, which closely resemble the designs found on the Bug Blox.

It later appeared as an AntiSora, and finally as a Shadow.

Personality
It speaks very little in the series, so its exact personality is unknown. However, it has expressed a veracious hunger for power as well as Hearts. It also seems to thrive on rage and hatred, perceiving them as exquisite fuel to increase its power.

Kingdom Hearts
After Sora, Donald, and Goofy track Riku down to the Great Hall, they learn that he has been possessed by the false Ansem and used the incomplete Keyblade of People's Hearts to summon the Keyhole of Hollow Bastion. He reveals that Kairi's lost heart has been within Sora all along, and that it must be released in order to complete the Keyhole. He moves to release Kairi's heart by using the Keyblade on Sora, but Sora parries at the last second, and eventually drive off Ansem.

However, with Sora unable to seal the incomplete Keyhole, he resolves to use the Keyblade of People's Hearts on himself. This releases Kairi's heart from Sora, reviving her, but also completes the Keyhole and casts Sora into darkness, transforming him into a Heartless while creating Nobody Roxas. Sora fades into a Shadow, as he does not have that much darkness in his heart, just as Kairi awakens, and the Heartless rapidly emerge from the Keyhole, forcing Kairi, Donald, and Goofy to flee.

As a Shadow, Sora follows his friends through the Lift Stop to the Entrance Hall, where he sees them being overrun by other Shadow Heartless. He rushes to help his friends, and though Donald tries to attack him, Kairi recognizes him and embraces him (in the manga, Kairi jokes that she recognized Sora's Heartless by the shape of its calves). Her light and heart return Sora to his human form, and Sora later states that while a Shadow, he nearly forgot everything.

Kingdom Hearts: Chain of Memories
When they first enter Castle Oblivion and learn of its alleged power over memories, Goofy reassures Sora by reminding him that he didn't lose his memories when he became a Heartless. Axel later explains to Larxene that this strange trait is what interests him about Sora. Sora and his friends eventually discover that the witch, Naminé, somehow has the ability to manipulate memories, allowing her to manipulate the memories of Sora and his friends.

Organization XIII are forcing her to do this in order to brainwash Sora at Castle Oblivion, but Sora defeats the Organization members within the castle and rescues Naminé. They agree that Sora will be put to sleep so that Naminé can restore his jumbled memories, and after Naminé puts Sora to sleep, she blanks the contents of Jiminy's Journal, as well as Sora and his friends' memories, then begins restoring them. However, while the memories were reconnected, the Journal itself remained blank. This is later revealed to be due to the record of Sora's Heartless beginning to assert itself.

Kingdom Hearts II
One year later, the Replica of Sora's Nobody, Xion, is reunited with his Nobody, Roxas, and the pivotal creation of Sora's Heartless later appears within Roxas's final dream-memories. Finally, Roxas reunites with Sora, and Sora reawakens as a complete being. Although he is whole, his time as a Heartless and the magic of his new clothes allows him to infrequently assume the Heartless-based Anti Form.

Kingdom Hearts coded
As a symptom of the secrets that were hidden within the journal, the digital recording of Sora's Heartless gained new life and, like Data-Sora, evolved into more than a simple facsimile. To that end, the Heartless absorbs both the Bug Blox which spread throughout the Data Worlds and the minds of the slain digital Heartless, increasing its power exponentially.

After clearing the Bug Blox from the data Hollow Bastion, the Journal alerts Data-Sora to a source of the Bugs: Sora's Heartless. Upon defeating Maleficent and Pete, Sora's Heartless's origins are revealed along with its intent to enter the real world to feed on hearts.

Data-Sora attacks the digitized Sora-Heartless, causing it to evolve into AntiSora before resuming its Darkside-like form as Data Sora is worn out from the fight. Just as the Heartless is about to win the fight, King Mickey appears and helps Data-Sora slay it by holding the vessel in place so the latter can destroy the Shadow that is his opponent's true form.

Kingdom Hearts 3D Dream Drop Distance
It makes a brief appearance where it attempts to obstruct Riku from entering Sora's Dream World and later takes over Sora's body, which is clad in Ventus' Keyblade Armor, to battle the Keyblade Master but is ultimately defeated.

Powers and Abilities
Originally, Sora's Heartless did not have any special abilities or traits to differentiate itself from that of a standard Shadow. But as the series progresses, it gradually grows in strength and power by feeding on the souls of Heartless that are slain by its lighter counterpart, Sora. Its power is first shown when Sora undergoes his Anti-form. In that form, The Heartless demonstrates impressive strength and tremendous speed. Since it cannot wield the Keyblade, it primarily relies on its clawed hands, feet and blasts of Dark Magic to compensate. In Kingdom Hearts Re:coded, once it absorbed the power of the slain digital Heartless and the Bug Blox, its powers are exponentially increased and expanded. In its Neo Darkside form, it can release shockwaves that can take the form of fiery waves, balls of fire, and waves of icicles that race across the ground. It can also rain down massive beams of Light energy, making it the only Heartless to ever use the power of Light, as well as fire large blasts of Dark energy from its fist. It can also teleport parts of its body (such as its fist) to take its opponents by surprise and even teleport underneath its opponents to take them off guard and hit them with a powerful shockwave. As Anti-Sora, It wields its own Dark construct of the Kingdom Keyblade. It is shown to be incredibly fast and mimics many of Sora's attacks. It is capable of telekinetically manipulating two ghostly Keyblades(in a fashion similar to Sora's Final form) to simultaneously attack and defend. It create copies of these Keyblades to rapidly fire at its opponent while encased within an invincible shield, until it summons a massive golden Keyblade that causes a enormous explosion. It can also travel through shadows and can even clone itself.

Trivia

 * Though it has not been confirmed yet, Kingdom Hearts fans believe that Sora's Heartless may be one of the members of the True Organization XIII, seeing how the Organization was planning on making Sora the 13th Xehanort.
 * Sora's Heartless is also the second human-based Heartless in the series to express sentience, the first being Xehanort's Heartless, Ansem: Seeker of Darkness.
 * Sora's Heartless is the only Heartless (save for Angel Stars) that is capable of using the power of Light, making it a virtual anomaly among Heartless.
 * A major difference between Sora's Heartless and Ansem: Seeker of Darkness. While Ansem seems to retain Xehanort's personality, appearance and memories, Sora's Heartless behaves nothing like Sora, and only seems to understand negative emotions as well as an instinctive lust for power. It also doesn't share Sora's form until later in the series when it attains more power. Though both Heartless were created through the same method, it is possible that due to Sora being a fledgling Keyblade Wielder at the time(whereas Xehanort is a seasoned Keyblade Master), it may have impacted his Heartless' personality.
 * The Anti-Sora Heartless also shares interesting similarities with the Beast of Darkness from Berserk. Both creatures were incidentally created by the main hero due to unique circumstances and represent their innermost darkness. The Beast and the Heartless also draw strength and gain greater influence whenever their more heroic counterparts slew their enemies. For instance, the Beast originally fed upon Guts' hatred, rage and bloodlust but after fusing the Berserk Armor,  it continuously procures power every time Guts kills supernatural beings such as Apostles, demons, ghosts, etc.  The Heartless also increases in power by feeding on the minds of Heartless slain by Sora.  Both have also manifested their powers through the magical attire of their hosts (Guts and the Berserk Armor/ Sora's Drive outfit).