First of all, if you haven't played Golden Sun, or haven't read the instruction booklet, you must have no clue what a Djinn is, right? Well, first thing you have to know, is how to use the word Djinn. See, Djinn is a plural word. The singular form of Djinn is Djinni.

Now you know who to use the word Djinn, I'll explain what it is. In the world of Golden Sun, 28 elemental creatures lurk around the continent of Angara and Gondowan. These elements are Venus(earth), Mercury(water), Mars(fire) and Jupiter (wind). Each have special powers of their own. The person who finds one of these magical creatures, must prove they are worthy, thus having to battle the Djinn.