Sonic Blade

Sonic Blade (ソニックレイヴ) is an ability that appears in Kingdom Hearts, Kingdom Hearts Final Mix, Kingdom Hearts: Chain of Memories, Kingdom Hearts Re:Chain of Memories, Kingdom Hearts II, Kingdom Hearts II Final Mix, Kingdom Hearts 358/2 Days and Kingdom Hearts Birth by Sleep. Sonic Blade is a technique that lets the user execute a number of successive thrusting attacks. After the first attack, execute each successive attack by using the prompted command, usually totaling up to seven thrusts.

In Kingdom Hearts and Kingdom Hearts Final Mix, selecting Sonic Blade from the last command box activates the first attack, and if it connects, the command box will change to Rave. Selecting Rave executes the next attack in the sequence. Rave appears five times, if all the attacks connect, and is then replaced with Blast, which executes the powerful finishing thrust. Totaling seven blows counting the very start of the attack. In Kingdom Hearts: Chain of Memories, pressing at the end of each thrust executes the next, for up to six additional attacks. In Kingdom Hearts Re:Chain of Memories and Kingdom Hearts Birth by Sleep, each attack after the initial thrust is activated by pressing at the prompt, for up to six additional attacks. In Kingdom Hearts II Final Mix, selecting Sonic Blade from the Limit menu with activates the first attack, and using the Rave Reaction Command executes the next attack in the sequence. Rave appears five times, and it is then replaced by the Finish Reaction command, which executes the final attack. Sonic Blade costs 3 AP and 2 MP bars in Kingdom Hearts and Kingdom Hearts Final Mix, and it costs 60 MP in Kingdom Hearts II Final Mix. In most of its appearances, Sora is completely invincible during the whole limit, making it just as useful as Strike Raid, should you lock on to different targets interchangeably with great skill.

Kingdom Hearts and Kingdom Hearts Final Mix

 * Sora learns Sonic Blade after defeating Cerberus at Olympus Coliseum.

Kingdom Hearts: Chain of Memories

 * Sonic Blade is an Attack Sleight that can be learned when Sora reaches level 22.
 * Its card combination is:

Kingdom Hearts Re:Chain of Memories

 * Sonic Blade is an Attack Sleight that can be learned when Sora reaches level 27.
 * Its card combination is:

Kingdom Hearts II Final Mix

 * Limit Form has Sonic Blade as a default ability accessible from the Limit menu.

Kingdom Hearts Birth by Sleep

 * Sonic Blade appears as an Attack Command for all three characters.

Recipes

 * Air Slide (LVL 4) and Blitz (LVL 4)-90% - Type N Recipe
 * Dark Haze (LVL 4) and Blitz (LVL 4)-90% - Type D Recipe (This Meld is only usable on Terra)
 * Thunder Surge (LVL 4) and Fire Dash (LVL 4)-90% - Type K Recipe

Kingdom Hearts and Kingdom Hearts Final Mix
Cloud uses a powerful version of Sonic Blade as one of his special attacks.

Kingdom Hearts II
Genie's Limit when he is in Valor Form is called Sonic Rave. The technique transforms Genie into a giant fist and Sora slams him into the ground repeatedly.

Kingdom Hearts 358/2 Days
Although Sonic Blade cannot be performed by any playable character, Xion in her First Form can perform a midair three-strike Sonic Blade and will only stop when any part of it misses or gets blocked.

Trivia

 * Like some of Sephiroth's attacks in Kingdom Hearts, the Sonic Blade attack makes an appearance in Dissidia Final Fantasy as one of Cloud's Brave attacks.
 * Since Rave appears as a command for the US version of the move(Sonic Rave is the JPN name), it can be stated that the Sonic Blade is composed of six 'Sonic Raves' ending with a more powerful 'Sonic Blast'. This is still up for debate however.