These four are on a journey to the west, to look for the scrolls. They fight demons and hopefully reach the west in one peice.
These demons try to stop Sanzo from getting the scrolls. They also need the scrolls to revive Kougaiji's father, Gyumao.
These three try to make a new world, knowing that it will cause the old one to collsape, and the people inside to die. But they also need the scrolls in order to do that.
These people are those that would not fit in the other categories.
These people look down from the heavens to make sure everything is right and not destroyed.