Antiform

AntiForm (アンチフォーム) also known as Anti-Sora, is Sora's Heartless from Kingdom Hearts II. It happens based on a hidden counter that increases as you use forms (but drastically decreases every time you use Final Form), and has no abilities. The form takes on the appearance of Anti-Sora from the first Kingdom Hearts game, only without the keyblade and with a dark mist rising from Sora's hands. Furthermore, unlike the Anti-Sora in Kingdom Hearts, his movements are somewhat feral in manner, as he runs about on all fours and attacks with his hands as though they are claws.

Most believe that this Drive Form exists due to Sora becoming a Heartless, specifically a Shadow. This is actually confirmed by Tetsuya Nomura in the Kingdom Hearts Ultimania guide. Since his movements in this Form are remniscent of that of Shadows and Neoshadows, this Drive Form is essentially the closest he ever gets to turning into a Heartless once more.

While Sora is extremely fast in this form, he can't attack with the Keyblade, instead he use his claws and feet, and can only revert when not in battle. It uses ALL of Sora's remaining Drive Gauge, and takes both party members. Note that if Sora consumes drive orbs while in this form, his Drive Gauge will decrease even further. It also makes Sora more vulnerable to damage, and his attack power drops, but his combo length is longer than most other combos in the game (Final Form can get in more hits at its higher levels, but it is very fast, and ends quicker than the Anti-Form combo). Anti-Form cannot be levelled up, and has no specific abilities, but pressing will make him do a Dodge to Forward Lunge attack (Anti-Glide). One more threat is that Sora can't use magic or items, meaning he can't be healed. Midair Doom and Dark Finale deal Dark magic damage, but this doesn't count, due to them not being in the magic menu.

Many say that the way to trigger Anti-Form is by getting hit by Heartless while in other drives, such as Valor, Wisdom, or Master. However, this is wrong, and has been proven that the way to turn into Anti-Form is by repeatedly Driving into any but Final Form, racking up Anti-Points.

It is wise to not rack up Anti-Points before a boss battle because even though Sora deals lots of damage with Anti-Form's long combos, as he is more vulnerable to damage and can't be healed.

Growth
Pros
 * Great enhancements in speed.
 * Fast combos and high damage dealer, given sufficient time for combos.
 * Speed of attacks keep certain enemies from attacking back.
 * Is the best of any Form at deflecting attacks with its own attacks (with the exception of Final Form and Limit Form); a Berserker's whole multi hit combo can be countered with no damage by using Anti's midair combo.
 * Can stay in the air for a noticeable amount of time.
 * Adds extra difficulty for those who want it.
 * Anti Glide is a helpful dodging ability, and it homes in on distant away opponents.

Cons
 * Occurs based on amount of Drive Form usage. Slightly random, excessive Driving will cause a greater chance of driving into AntiForm, but without a boss battle or Keyblade multiplier, there is never a 100% chance of driving into AntiForm.
 * Completely drains the Drive Gauge.
 * Can only be disabled when the Form Gauge has wholly emptied. This can be accelerated by gathering HP, MP, Drive and Munny Orbs. Another way to exit the Form is to simply leave a combat-capable area for a non-combat one.
 * Inability to heal in any way.
 * Long combos take time to deliver finishing blows.
 * Close-range attacks puts Sora in risky situations.
 * Not all attacks cause hitstun(enemies will simply be standing and free to move as if they are not being attacked)
 * Both partners cannot be used during this drive.
 * Magic is disabled.
 * Defense is lowered, damage dealt is twice as great as normal.
 * Strength is lowered.
 * Reaction Commands can't be used.

Formula For Triggering Anti-Form

 * Fights in which Anti-Form never occurs: Pete (all fights), Barbossa (Port Royal), Hades, all battles involving outside characters (i.e. Mickey, Hercules, etc.)
 * Note: Once the scene where Sora battles Roxas (After you fight him in Final Mix+) has occurred, as long as the Two Across Keyblade, acquired from winning the battle and which bears the "Light and Dark" ability, is held, there is a 25% chance you will get Final Form instead. If you still get Anti-Form, it increases to 50%, and then 100%. Also if you are in MP Charge mode, it's a 100% chance you will go into Anti-Form if you are in a boss fight unless you turn into Final Form.

Helpful tips

 * Press during ground combos. This will move Sora around fast and keep the enemy from being able to retaliate many times. Plus, it keeps the combo going.
 * Don't be afraid to run when you are in AntiForm. AntiForm is actually quite good for running/avoiding attacks. But do NOT use Anti Glide, it will move you closer to opponents instead.
 * Anti-Glide is a great way to dodge attacks, even Xaldin's lance slashes.
 * Using AntiForm's ground combo will allow it to move into attacks that cause enemies to be stunned faster.
 * Aerial Recovery can still be used in AntiForm.
 * AntiForm does not bounce off when attacking Large Bodies head-on.

Representation
This form represents the darkness that dwells within Sora's heart and his time of having been turned into a Shadow Heartless.

Adaptive Forms

 * Despite showing almost no distinctive appearance apart from Sora's shadow, the Anti-Form's appearance does indeed change in different worlds:
 * Halloween Town: In Halloween Town the Vampire mask takes the form of a Shadow Heartless.
 * Christmas Town: In Christmas Town, the Anti-Form changes Sora's Santa costume completely to black, a Heartless emblem can be seen on top of the hat though. (Applies only in Final Mix+)
 * Space Paranoids:In Space Paranoids, the Anti-Form changes the armor completely black and the circuits to dark purple.
 * Timeless River::*In Timeless River, the Anti-Form appears as a retro cartoon silhouette.

Trivia

 * Anti-Form looks very similar to Anti-Sora in the first game (Kingdom Hearts), only without a Keyblade.


 * In Kingdom Hearts II: Final Mix+, during the fights against Vexen's Absent Silhouette and his data copy Vexen can make copies of Sora that are actually Sora in Anti-Form.


 * Anti-Form is the only form that doesn't level up, and Sora doesn't get experience from enemies killed.
 * Aside from Riku, Anti-Form is the only Player/Party member that may use dark-based magic attacks.
 * Though killing a boss with other forms will result in Sora being in the next cutscene in the mentioned form, being in Anti-Form will revert Sora back to his normal stage (with 0 Gauge)
 * AntiForm's Drive Gauge never rises above 6.
 * The move used when pressing during Anti's ground combo is considered magic, and will not hurt Sorcerers.