Superiority complex is nothing but an exaggerated form of inferiority complex. When a person develops too much of inferiority complex, then it turns into superiority complex. In superiority complex, the individual feels that a good way to overcome inferiority is to make others feel inferior and thus become superior.
You can read up a bit more on the topic here, Davita.
http://www.lifeandpsychology.com/2009/02/inferiority-and-inferiority-complex.html
I have a rather delightful image of Davita mounted on a steed riding around modern day Indonesia wearing a pith helmet while brandishing a musket.