Unlike other Drive Forms, Anti Form cannot be purposefully activated. Instead, it will be randomly activated when Sora attempts to enter Valor, Wisdom, or Master Form, based on a hidden
"Anti Point" counter. This counter is increased by 1 every time Valor, Wisdom, or Master Form is activated, but is reduced by 10 when Final Form is used. Gameplay-wise, the Anti Form exists as a consequence of abusing the Drive system, and is meant to be "strong but troublesome".
[2] Anti Form is also the only Form that will activate if Form is used while in MP Charge state, though once Final Form is made available it can also appear. However, the counter system is ignored while the
Two Become One Keyblade is equipped, as its
Light & Dark ability will make it so only Anti Form or Final Form activate when Form is used. Anti Form starts at having a 75% chance of being the activated form when Form is used in this state, but goes down to 50% and then 0%, until Final Form is obtained.
Anti Form can only be manually deactivated outside of battle, though its Drive Gauge caps out at 6, and consuming Drive Orbs will actually cause the gauge to be consumed faster. In addition, though Drive Forms normally persist through cutscenes and
Cup seeds, Anti Form will instead revert back to Standard Form. Anti Form is also unique among Forms in that while it possesses the "Anti-Glide" Growth ability, it cannot be leveled and is thus inaccessible in Standard Form. Like Valor Form, Anti Form cannot use magic, but it is also unable to use items. To top it off, Sora cannot pick up HP Balls while in Anti Form, meaning it is completely unable to heal in any way.
Anti Form is strongly reminiscent of the
AntiSora Heartless from the first
Kingdom Hearts, and Nomura has confirmed in an interview with
Famitsu that Sora's ability to enter this form is due to his transformation into a
Shadow.
[2] Specifically, though, Sora's Anti Form has more feral behavior in which it runs about on all fours, and instead of using the Keyblade in this form, Sora attacks with claws on his hands. Aesthetically, Sora's skin and hair become ink black, his eyes glow yellow like a Heartless, and his clothes become black with blue accents. Furthermore, he constantly emits Darkness from his arms and back in the form of misty black and violet wisps.
represents the darkness that still dwells within Sora's heart