Hidden "Teleport" Spell
To get the hidden spell, Teleport (it can't be gotten in any other way), get into a battle somewhere on the Adventure Map. Next, go into your Spellbook and select a spell. Now, press the ''B'' button. After the battle, get into another one and you will see that you have the spell in your Spellbook. Note: This cannot be done in a Siege Battle. It won't hurt your game, but it won't work, either.
Random New Spells
To randomly get new spells in your spellbook, cast a spell in battle so it takes you to the battlefield asking you where to cast it. Then hit the ''B'' button so it cancels the spell. Then go check your spellbook. You will have a new spell at the end of your book. NOTE:Sometimes the spell will be ''Teleport''. Teleport is a spell which will not work and your game will freeze.