Select magic SPECIAL on options.

Get the minimum amount of books from mages When killing the boss at stage 1, hold magic button Don't release it. After the black screen, you can release it. Don't get all books, only 1 book (if you have none), or it will not work. Wait until camp ends with 3 books on the ground. As soon as you get control of your character, he/she will release a level 1 magic. If it worked, you'll see 2 lines of magic bars

Clip of how to do it:

Obs: When using Ax, if you hold more than the max magic possible of the character, game will softlock. Obs 2: When using Tyris, if you hold more than the max magic, she will use other character magic, but if you hold too long, she will softlock too.