Rarity is just a normal humanoid robot who is just living life with her little sister Sweetie Belle. Her bestfriend Rainbow Dash, attends the same high school with her.
But recently she discovers she had a secret battle mode. And coincidentally enough for her a week after she finds out about these settings the peaceful city of Canterlot comes under attack by a slew of evil robots. Which the people have dubbed The Legion of Robot Masters.
Now she has to balance the job of protecting her home and dealing with her personal life.

Characters are slightly different from cannon.
Takes place 1 year before Twilight sparkle crosses over to the human world.