Second Form

Second Form is a Formchange in Kingdom Hearts III. It grants Sora clothing based on his outfit from Kingdom Hearts II and gives him access to familiar abilities. It is triggered by the Kingdom Key, Starlight, Midnight Blue, Phantom Green, Dawn Till Dusk, Elemental Encoder, and Advent Red.

Although each of these Keyblades has a nominally different Formchange determined by the Keyblade — "Second Form", "Second Form S", "Second Form M", "Second Form P", "Second Form D", "Second Form E", and "Second Form A", respectively — only Second Form S actually differs from the others.

Design
Second Form changes Sora's clothes into the same colors and style of the clothes he wore in Kingdom Hearts II. While wearing his original outfit during the Olympus episode, Sora's clothes do not change. In addition, when using the max-level Shotlock, Sora's clothes will also briefly change to his Kingdom Hearts II style, even when not in Second Form.

Mechanics
Second Form grants Sora several of his abilities from Kingdom Hearts and Kingdom Hearts II that are otherwise unusable outside of the Formchange. At any time, Sora can use a situation command finisher that will also terminate the Formchange. Each time he fills the Situation Gauge, this finisher is replaced with a more powerful finisher—first Stun Impact, then Sonic Blade, and finally Ars Arcanum, or Ancient Light in the case of Second Form S. If Sora has Falling Slash, Quick Slash, Flash Step, Radial Blaster, Aerial Sweep, or Aerial Dive equipped, these abilities will be incorporated into Second Form's combos.

Strategy
Second Form is best suited for single target ground encounters or battles that give Sora breathing room to focus on one enemy at a time. When used for battling hordes, the player should focus on airborne enemies as this allows Sora to use Magnet Burst to drag in more enemies around him to no only do more damage, but to also fill up the situation bar faster. This tactic is especially useful for Second Form S because its third-level finisher, Ancient Light, allows Sora to annihilate groups of enemies faster.

Although Ars Arcanum deals significantly more damage than Sonic Blade and Stun Impact, the former two can still be useful during low HP situations for the invulnerability they grant.