Thundara is learned after defeating Ursula for the last time in Atlantica. Thundaga is learned after beating Cerberus in the Hades Cup at the Olympus Coliseum. Cerberus is the second boss and the twenty-ninth fight in the series.
All About Thunder Magic in KH1
The Thunder spells in Kingdom Hearts are area-of-effect (AOE) lightning attacks. They’re perfect for cleaning up small fry or dealing damage to tougher groups. Each cast of a Thunder spell costs 1 MP. And as usual, Donald learns new Thunder spells every time Sora does.
How To Learn Thunder
Thunder is learned after clearing Phil’s barrel training in the Olympus Coliseum. Doing the training is the first thing you’ll do when you arrive, so it’s just about impossible to miss. Thunder has a small AOE but is especially useful against enemies that crowd around Sora, such as Powerwilds or Shadows. Thunder’s damage formula is as follows:
How To Learn Thundara
You get Thundara after defeating giant Ursula in Atlantica. She’s the final boss of the world, so it’s hard to miss if you’re just going through its story. Thundaga covers a wider area and has bigger bolts. It also has a good boost to damage, which follows this formula:
How To Learn Thundaga
Thundaga is learned after beating Cerberus in the Hades Cup. The three-headed K9 is the twenty-ninth fight. To unlock the Hades Cup you need to clear the Phil, Pegasus, and Hercules Cups, and lock the keyhole in Hollow Bastion. Chip and Dale will inform you of the new tournament on the world map when you meet the requirements. Thundaga darkens the sky and strikes a wide area with big beefy bolts, dealing large damage to anything caught in it. Its damage formula is as follows:
Is Thunder Magic Worth It?
The interesting thing about the Thunder spells is that they’re entirely optional. Kingdom Hearts 1 is set up in a way that you don’t ever have to visit the Olympus Coliseum or Atlantica at all. Like, ever – you can just fly around them to the other, required, worlds. Because of this, it’s up to you if you want to learn the spell. Remember, it is learned sequentially, so if you skip the Coliseum and beat Atlantica first, you’ll learn Thunder from Ursula and then Thundara from Phil’s Training. However, it is not recommended to skip this spell: Thunder is super useful. If Sora has a lot of MP you can wipe out whole groups of heartless in just a few casts. Thunder and its upgraded forms are perfect for wiping up smaller enemies in your way, and a tremendous tool when farming for synthesis items. Just because you can skip it doesn’t mean you should. It’s just too good!