Fire obtained after defeating Guard Armor in Traverse Town. It’s a necessary story boss fight, so you can’t miss it.
Fira obtained after defeating Genie Jafar in Agrabah. Again, this is a mandatory boss, so you shouldn’t miss it.
Firaga given to Sora after he locked the last keyhole. As with all fire spells, it cannot be missed and is part of the story progression.
Donald also learns every Fire spell at the same time as Sora.
A Closer Look at the Fire Family
Notes: All damage formulas reflect the Final Mix version of the game
All Fire spells cost one MP.
Fire is obtained right after meeting Donald and Goofy and defeating Guard Armor in Traverse Town.
Its damage is determined by the following formula:
Max MP + 20 Sora = spell power
Fire has a bit of homing and a quick cast, which makes it a great choice against flying foes.
Fira is obtained after defeating Genie Jafar who is the last boss in Agrabah.
The breakdown uses a similar formula:
Sora’s Max MP + 28 = spell power
Fira is a bigger fireball and has better homing than Fire.
Firaga was given to Sora by the Princesses of Heart after locking the last world. It’s near the end of the game.
The damage formula is as follows:
Max MP Sora + 36 = spell power
The biggest Fire Spell is a massive explosion that deals massive fire damage to one enemy. Still very useful against enemies that fly and can fire something weak against heat.
Are Fire Spells Worth Using?
Ultimately it depends on what you are up against and how your Sora is built.
Taking down non-fire flying enemies is a lot easier with spells, but if you’re not careful, you can easily blow up all your MP.
If your Sora is more inclined towards magic and has strength and MP, then Fire and his friends will be your bread and butter.
If you’re more of a physical fighter than I’d suggest keeping Fire in your shortcut bar and having it only for swatting the occasional fly that might get under your skin.