Drive Form

Drive Forms(ドライヴフォーム|Doraivu Fōmu) are special forms that appear in Kingdom Hearts II. Through the magic of the clothes that Flora, Fauna and Merryweather gave him at the Mysterious Tower, Sora is able to temporarily take on a new appearance that grants him a separate set of abilities, often through merging with his allies. Sora's use of Drive Forms is mechanically similar to Riku's Dark Mode or Terra, Ventus, and Aqua's Command Styles.

Description
Entering a Drive Form immediately refills Sora's HP and MP Gauges, but more significantly, it gives his outfit a style bearing the color and symbols of that Form, while replacing his normal Action and Growth abilities with a new list of Action, Growth, and Support abilities unique to that Form. These changes can go so far as to grant dual Keyblade wielding or variations of Sora's Magic spells. Each Form gains experience and levels up in a unique way, independant of other Forms and Sora's own experience level, and every Form excluding Anti Form can reach Level 7. In addition, every Form has an associated Growth ability that grows as the form does, and, with the exception of Anti Form, upgrading the Form's Growth ability allows Sora to use that ability in his Standard Form, albeit at a lower level.

Drive Gauge
The Drive Gauge determines the length of time that Sora can remain in a Drive Form. It is filled by picking up Drive Orbs, but it begins to continuously drain once Sora enters a Drive Form. However, Sora can still pick up Drive Orbs to replenish a small portion of the gauge and prolong the Drive.

Forms
There are six Drive Forms in total. Five can be triggered from the Command Menu, but the last one is random. The Drive Forms are:

Valor Form: Valor Form allows Sora to wield two Keyblades of the player's choosing at the same time. It specializes in physical combat, but can't cast spells, contrasting to Wisdom Form. Its special ability is the High Jump, which can also be obtained for normal Sora at higher levels. Sora wears red clothes with a red fleur-de-lis symbol. It uses Goofy's power and is based on him. Sora's running speed is noticeably enhanced in this form. As mentioned, this form gains experience with each successful hit on an enemy, making it the easiest form to level up. Sora gains this form when he obtains his new clothes from the fairies at Yen Sid's Tower.

Wisdom Form: Wisdom Form lets Sora float across the ground like on a skateboard, and uses a single Keyblade to shoot enemies with magical bullets, but not physically strike. It is a Magic-based form, in contrast to Valor Form's physical combat. Its special ability is Quick Run, which is a fast dashing technique to move quickly through areas or dodge attacks. Sora wears blue clothes with flame symbols on it. It uses Donald Duck's power and is based on him. This form gains experience whenever a Heartless is destroyed. It is obtained after Timeless River is completed.

Limit Form: Limit Form is a form based on Sora's old clothes; it is exclusive to Kingdom Hearts II Final Mix, though. It uses abilities from Kingdom Hearts and Kingdom Hearts Final Mix that didn't appear in Kingdom Hearts II. Its special ability is Dodge Roll, a small leap forward that defends Sora from all attacks (and reflects projectiles). The color scheme of Sora's clothes in this form change to that of his original clothes from Kingdom Hearts to reflect this. When triggered, both partners stay by Sora's side and do not disappear, making it especially useful during tough battles. This form gains experience whenever a Limit Finisher Reaction Command is used. It is obtained when Sora obtains Oathkeeper in Twilight Town. This is the only form that Sora can trigger alone.

Master Form: Master Form is a combination of both Valor and Wisdom forms. It uses two Keyblades, one controlled through telekinesis and the other with the hand. It specializes in both Magical and Physical Combat. Its special ability is Aerial Dodge, a midair jump that blocks attacks (and reflects projectiles). Sora wears yellow clothes with a cross motif. It is based on King Mickey and uses both partners. This form gains experience via collecting Drive Orbs. Every small orb is worth 1 EXP while every big orb is worth 3 EXP. It is obtained in Hollow Bastion by speaking to King Mickey before the Battle of the 1000 Heartless and during the events of Space Paranoids.

Final Form: In Final Form Sora again wields two Keyblades, this time both through telekinesis. It is equally strong in both strength and magic, and is considered the strongest amongst all the other Drive Forms. Its special ability is Glide, which allows the user to fly briefly. Sora wears silver clothes with the symbol of a crown. It is based on Roxas's fighting style (Final Mix) and uses both characters. This form gains experience whenever a Nobody is destroyed, possibly making it the hardest form to level up. It is obtained randomly after Sora fights Roxas in The World That Never Was; while the first occurrence of the form is random, it can be accessed at any time afterwords.

Anti Form: Anti Form is the only form when Sora is without his Keyblade. It specializes in fast attacks and many combos, but lacks the ability to cast spells, shield, recover HP, or use Reaction Commands, which is sometimes required to end boss battles. It appears when one tries to Drive, the possibility of it appearing depending on the Anti Points (a hidden counter, which increases with each Drive by one point except by Anti and Final Forms). However, using the Final Form will reset this occurrence and lower the chance of it happening. It has no special ability, is the only form that can not be triggered through the Command Menu, and Sora loses the ability to perform Reaction Commands, which can be especially troubling when certain enemies can only be defeated through them. In this form, Sora becomes completely black with yellow eyes, as well as having a dark mist rise from his body, and he moves like a Shadow Heartless, resembling the AntiSora boss from the original Kingdom Hearts. It uses both partners and consumes all of the Drive Gauge. This is the only form that cannot level up, and the only one that Sora cannot change back from at will; once this form is activated, Sora is stuck in it until the Drive Gauge runs out, until he exits the battlefield, or until the battle is over. It should also be noted that if Sora dies in this form, he dies as his normal self. The Anti Form can be considered a double-edged sword; while Sora is very fast, his attacks are significantly weaker, he takes more damage than usual when struck, and his movement and fighting style become more feral and less human, running around on all fours and attacking with his hands as though they were claws. Many fans have speculated that this form exists due to Sora's brief transformation into a Heartless, and Tetsuya Nomura has confirmed this: essentially, the Anti Form is the closest that Sora ever comes to becoming a Heartless once again. It is also worth noting that in Halloween Town, the pumpkin mask on Sora's face turns into the face of a Shadow Heartless, with two yellow eyes on it.

Trivia

 * If Sora is in a Drive Form before a cutscene, he will appear in the cutscene in that Drive Form (the exception being Anti Form), although the actions in the cutscene are not changed in any significant way. He will also handle his main-handed Keyblade as he normally would, whether he has dual-wield capabilities with the form in question or not.
 * If Sora mounts a skateboard while in a Drive Form, he will not revert to his normal form even when the gauge is depleted.
 * In the room where Sora receives his new clothes, hints to future Drive Forms that he will receive later on can be found by examining the mirrors - each of the five mirrors around the room describes the abilities of one of Sora's original five Drive Forms, including his Anti Form. It should be noted that in Final Mix, an extra mirror is added for Limit Form.