Thunder

Thunder, Thundara, and Thundaga magic are attacks used by Sora, Donald, and other characters and enemies that utilize the element of Electricity. In Kingdom Hearts, Thunder was a more powerful and costly spell than Fire or Blizzard, summoning a barrage of lightning bolts from above to strike an enemy and any other enemies nearby. It cost 1 MP bar to use. In Kingdom Hearts II, Thunder is more or less equal to the other attack spells, summoning a single lightning bolt to strike one enemy. The area of effect increases with Thundara and Thundaga.

Thunder magic will be useable again in Kingdom Hearts: Birth by Sleep.

Kingdom Hearts
Thunder: Learned after completing Philoctetes. Power equals Max MP*2+14. Thundara: Upgraded after defeating the giant Ursula. Power equals Max MP*2+18. Thundaga: Upgraded after defeating Cerberus in the Hades Cup. Power equals Max MP*2+22.

Kingdom Hearts: Chain of Memories
Thunder: A Magic Card obtained after defeating Larxene for the first time. Thundara: Stock 2 Thunder Cards. Thundaga: Stock 3 Thunder Cards.

Kingdom Hearts II
Thunder: Defeat the Hydra (Olympus Coliseum) Thundara: Upgraded after the defeat of Storm Rider (Land of Dragons) Thundaga: Upgraded after the defeat of Groundshaker (Pride Lands)

Enemies that use Thunder Magic

 * Yellow Opera
 * Devastator
 * Bookmaster
 * Wizard
 * Ursula
 * Groundshaker
 * Larxene

Other Usage

 * In Kingdom Hearts, the Thunder terms are used to mark the ranks of the Blaster Gummi Blocks.
 * In Kingdom Hearts II, Thunder are used to mark the ranks of the laser-like Blaster Gummi Blocks.