Rage Form

Rage Form is a Formchange in Kingdom Hearts III. It has a chance to activate when Sora reaches critical health, regardless of current Keyblade.

Kingdom Hearts III
During Sora's final fight against Xehanort in Scala ad Caelum, Xehanort uses the power of Kingdom Hearts to absorb Sora's light, forcing him into Rage Form. By attacking Xehanort, Sora is able to regain his light.

Appearance
Rage Form turns Sora's clothes, skin, and Keyblade deep black, with glowing red eyes, an aura of darkness, and a fluorescent white swirling pattern on his pants. It is similar to AntiForm and envelops Sora's Keyblade in darkness for quick and powerful attacks. Unlike AntiForm that represents Sora's darkness in his heart, Rage Form is when Sora is in a rampage state, fueled by anger.

Mechanics
When in Rage Form, Sora can use Riskcharge as a situation command, raising his Strength, at the cost of depleting half his remaining health. After using Riskcharge three times, Sora gains access to Rage Form's finish command.

During the final fight against Xehanort, Riskcharge is unavailable. To obtain the Finish command, Sora must instead attack Xehanort enough to fully fill the situation meter.

Strategy
Entering Rage Form replenishes Sora's HP so it is useful when in low health.