Level

Your Adepts Level is determined by how many experience points they may have. The higher your level the higher all your other Statistics will be. The only way to increase your characters' level is by engaging in battles. Typically bosses yield more experience points that others, with the exception of the Phoenix monster line which is famous for dishing out large amounts of experience points. Although you should try to raise your current level quite a bit before you attempt a boss. In the Golden Sun series the highest level you can raise your Adepts to is Lv.99.