Magic 101(learn about magic here)

Fire: shoots a ball of fire out of your keyblade
Fira: shoots a more intense blast of fire out of your keyblade
Firaga:The most powerful fire spell that can come from a keybalde

Blizzard:Shoots a freezing blast at the opponent
Blzzara: more intense freesing blast
Blizzaga:Most powerful freezing spell

Thunder: Brings down a thunderbolt over the opponent
Thundera:Bring multiple thunderbolt down over your enemies
Thundaga:Bring down a barrage of thunderbolts on your enemies

Aero: A shield of wind around your body(dampening damage)
Aeroa:A more pwerful shield of wind
Aeroga:A shield of wind powerful enough to hurt your enemies upon contact

Slow:Slows down an opponent or ally
Slowaga:Slows down multiple opponents or allies

Haste:Speeds up you or opponent
Hastaga:Speeds up multiple opponents or allies

Magnet: Drags enemies to a focused point
Magnera: Drags more enemies
Magnega:Pulls enemies to the focused point,liek sheep for the slaughter
(not done with this yet)