Oz the Great and Powerful

Description:
A small-time magician is swept away to an enchanted land and is forced into a power struggle between three witches.
                                                                 
Awesome movie, first time in a Disney movie that it goes into the castle. At first I was confused on Theodora and Evanora, since I remembered the original movie so I was " who is the good witch that I can't remember a name to...neither look like her"...sure enough the movie helps explain 'everything'. The movie explains how the witches get the way they are in The Wizard of Oz, and how he is a floating head. Still confused on who the fourth witch is, since there are two wicked witches (west and east), and the witch of the south which is good....so I know the witch is from the north and should be good, but her name and what she looks like still no clue. I looked it up online, all I get are pictures of Glinda (south wrong direction), though that is who she is in The Wizard of Oz...I refuse that idea, since Glinda is the good witch of the South not North in the novels.