This story is a sequel to Rainbow Dash, Element of Magic

Diamond Tiara used to think she was special, until her best friend turned on her and called her special talent "worthless". Friendless, Diamond Tiara must make amends for her past ways while trying to figure out the truth behind her special talent, while finding true friends to help her and stand by her.

This is an alternate universe wherein Rainbow Dash is the Element of magic, and the lives of herself and her friends have been changed, along with their respective elements. However, despite being the Element of Magic, Rainbow Dash isn't Celestia's student....that title belongs to her childhood rival, Sunset Shimmer.

Is now the first story in the Rainbow is Magic verse!