Spoiler:tons of good items in the chests in the castle. You may want to play this a couple times and try to get the good stuff out of the chests. (If it is indeed the part where the castle is burning down)
Make sure you get a learner and learn Aqua rake in the smaller desert region. IT is a lifesaver when you have to fight desert types; Kill certain bosses in one hit. (mainly on world 1)