The AntiSora is a Pureblood Heartless that is found in Kingdom Hearts. It is a boss fought in the Captain's Cabin in Neverland.
Sora and his friends encounter Riku on Captain Hook's ship, where he reveals that he now has control over the Heartless. To prove it, he creates a Heartless replica of Sora before their eyes, and it throws them into the ship's brig. As Sora fights his way back to the ship's deck, he encounters many of these Shadow Sora's, which only he can defeat. However, they have no weapons and often vanish before he can even attack them. Once Sora reaches the Captain's Cabin, Riku creates a more complete replica of Sora, this one able to wield a shadowy Keyblade. After being defeated, it fades back into darkness.
The AntiSora is a near-perfect replica of Sora. It dresses in the same clothing as Sora, including his gloves, shorts, large shoes, hooded shirt, and even has the same necklace and hip chain. However, its clothing is colored entirely in shades of black and grey. Its skin is also black, as is its spiky hair. It carries a copy of the Kingdom Key, which is similarly dark-colored. It also has the glowing yellow eyes characteristic of Heartless.
The AntiSora's name reflects the fact that it is an antagonistic, Heartless copy of Sora. The prefix "anti-" means "against".
The spells recommended to set to shortcuts are Aero, Cure, and either Thunder or Stop. Thunder allows Sora to attack AntiSora wherever it may be, while Stop can freeze AntiSora for a short period of time. Unlike Sora, AntiSora is unable to use magic, but can instead transform into a flat shadow and move about in that state, as like the basic Shadow Heartless. It can deal a lot of damage if Sora is caught when it leaps back out of the ground. So be sure to keep Sora in motion or use the Dodge Roll ability to help avoid those attacks. After half of its HP is depleted, AntiSora creates replicas of itself to distract you, so use the Scan ability to help speed things up a little bit. But be careful, as those replicas can hit and do the same amount of damage the as the real AntiSora. Be sure to keep your HP within a tolerable level - heal when necessary. The Guard ability is particually useful if it is combined with the Counter Attack ability in this battle, as you can deflect some of AntiSora's attacks.