As with all items, discs are found randomly by killing enemies or smashing open boxes, or on the green merchant on Pioneer 1. If you are able to use the Technique at your level, the name of the disc will be white and you will be able to use it just like any other item. If you are unable to use it, the name will be gray and you will need to wait until a higher level to use it. It's a good idea to stash a unusable disc in the bank until you can use it. Foie A fire technique.
Ball of fire burns a single enemy.
Barta An ice technique. A penetrating linear ice attack. Zonde A lightning technique. Strikes a single enemy from above. Gifoie A fire technique.