Command Style

The Command Style is a new battle system that appears in Kingdom Hearts Birth by Sleep. Terra, Aqua, and Ventus have times when the Command Bar at the top of their Command Menu fills up after hitting enemies they can undergo a Style Change which grants increased strength and new Deck Commands. There are certain Command Styles that all of them can change into but they have their own unique Styles that only one can perform. Command Styles allow a different method for each of them to fight with either Magic or combo attacking.

Command Styles (LV1)
Upon meeting certain requirements while filling up the Command Gauge (located right above the Deck Command menu), a character may undergo a Style Change rather than executing a finishing attack. Every style change has certain requirements for activating; an example of executing Diamond Dust would be to fill up the last remaining portion of the Command Gauge with an Ice-based attack.

General
These are available to all three Keyblade warriors.
 * Thunderbolt: A swift Command Style that unleashes powerful lightning upon attacks. Activated by filling the Command Gauge with Thunder-based commands. The finisher consists of the user summoning a ball of light over his or her Keyblade then thrusting his Keyblade into it causing multiple lightning bolts to come out of the energy ball and raining down on enemies.
 * Firestorm: A ranged and versatile Command Style that focuses the Keyblade to erupt in flames while attacking. Activated by filling the Command Gauge with Fire-based commands. This was named Fire Blazer in the Japanese release. The finisher consists of the user jumping in the air, charging energy, and hurling a fireball that erupts into multiple pillars of flame.
 * Diamond Dust: An ice-based Command Style that seems to specialize in crowd-control and dealing with multiple enemies, named after the common attack of the Blizzard-based summon Shiva from the Final Fantasy series. Activated by filling the Command Gauge with Ice-based commands. The finisher consists of the user summoning a surrounding ice formation that shatter after a certain time and damages enemies.
 * Ice Blast: Another ice-based Command Style that uses an ice cream theme. Randomly activated by filling the Command Gauge with an Ice Cream item. The finisher consists of the user summoning multiple balls of ice that shatter after certain time and damages enemies.

Terra

 * Critical Impact: An exclusive powerful Command Style for Terra that utilizes slow, but heavy hits to their maximum. Activated by filling the Command Gauge with physical-based commands.The finisher of this Command Style is Terra jumping in the air, charging energy and slamming his Keyblade into the ground. The impact creates a huge shockwave.This was named Fatal Mode in the Japanese release.

Aqua

 * Spellweaver: Her own exclusive Command Style; it utilizes the power of light to to hover her Keyblade in midair, swiftly attacking enemies while enhancing her magic capabilities as well. Activated by filling the Command Gauge with a variety of multiple magic-based commands.The finisher consists of Aqua performing a magical spin attack that can be controlled with the analog stick. This was called Magic Wish in the Japanese release.

Ventus

 * Fever Pitch: Ven's personal Command Style that puts a large emphasis on overwhelming enemies with wide-ranged, speed-based combos. Activated by filling the Command Gauge with physical-based commands. The finisher of this Command Style consists of a long combo ending with five beams of light. This was named Speed Rave in the Japanese release

Command Styles (LV2)
While using a Level 1 Command Style, the player can further achieve a second level by filling up any specific Style Gauge. An example of how this would work is if Ventus finished Firestorms's Style Gauge with an Aero-spell - the result will be the powerful Cyclone Command Style.

Terra

 * Rock Breaker: Activated by filling the Style Gauge with Detona-based (including Brutal Blast) or Blade commands. A powerful and long-ranged Command Style that works best on the ground. The finisher of this Command Style is basically Terra summoning three large earth crystals from the ground and sending them to damage enemies.
 * Bladecharge: Activated by filling the Style Gauge with Fire-based, Ice-based or Strike commands. In this Command Style, the Keyblade resembles a purple sword. A long-ranged style, as its name implies, it allows the user to "charge up" the attacks for additional damage. The finisher consists of Terra spinning the blade to hit surrounding enemies, and then smashing it into the ground.
 * Dark Impulse: A Command Style in which Terra summons the power of darkness to attack enemies. A versatile Command Style that hits enemies with slow, heavy attacks, but also exhibits long-range projectile attacks. Activated by filling the Style Gauge with Dark- and Gravity-based commands. The finisher consists of Terra hiding in his shadow, appearing under his enemy perform an uppercutt with a dark claw. This command activates instantly when you battle Master Eraqus. Due to his connections to Terra, the new Xehanort can also use Dark Impulse during his battles with Aqua and the Lingering Sentiment. The name of this Command Style is shared with one of Riku's Duel Sleights in Kingdom Hearts Re:Chain of Memories.

Aqua

 * Ghost Drive: Aqua's high speed Command Style and exclusive to her; it allows her to attack enemies at high speeds while using after-image illusions and tricky movements to her advantage. Activated by filling the Style Gauge with Thunder and Magnet-based commands. The finisher consists of Aqua circling certain area before creating an explosion.
 * Bladecharge: In this Style, the Keyblade resembles a Light-blue sword. A long-ranged style, as its name implies, it allows the user to "charge up" the attacks for additional damage. Activated by filling the Style Gauge with Fire and Ice-based commands. The finisher consists of Aqua spinning blade before smashing it into the ground.
 * Sky Climber: A style that gives Aqua a great midair advantage, it allows her to ride her Keyblade around to attack foes from above at high speed. Activated by filling the Style Gauge with evasive, or Zero Gravity-based commands.The finisher consists of Aqua mounting her Keyblade and hitting multiple enemies before heading skyward then crashing back down and finally, spinning on herself causing a small tornado. This was named Air Rider in the Japanese release.

Ventus

 * Cyclone: After meeting certain requirements, Ven's initial Command Style morphs into much more powerful Cyclone Command Style, attacking surrounding enemies with spin attacks. Activated by filling the Style Gauge with Raid, or Aero-based commands. The finisher consists of Ventus spinning hitting enemies around like a cyclone.
 * Wingblade: An omni-directional Command Style designed to combat multiple enemies from all directions with a wingspan of phantom swords.The finisher consists of Ventus jumping in the air with his blade pointed downward; Ventus lands and causes a flash of light that damages nearby enemies. Bears a resemblance to Riku and Sora's "Session" limit. Activated by filling the Style Gauge with Blade (eg.Blizzard blade), counter, or Magnet-based commands.
 * Sky Climber: A Command Style that gives Ven great midair advantage, it allows him to ride his Keyblade around to attack foes from above at high speed. Activated by filling the Style Gauge with Dash commands or Zero Gravity-based commands.The finisher consists of Ventus mounting his Keyblade and hitting multiple enemies before heading skyward then coming back crushing down and finally, spinning on himself ;causing a small tornado. This was called Air Rider in the Japanese release.