I liked the story! Derpy Hooves would be considered an Oc formed with a background character. one thing, never leave Derpy alone with Pinkie, ever! Who knows what crazyness those two would get into?
"The sky is dark. The is no sun, moon, or stars. It's been like this for as long as we can remember. My friends and I have vowed to find and bring back High Princess Sunstar. Only she has the power to end the night. We six fillies have no marks of our own. We must succeed or else, Equestria will freeze." Aurora Dawn. Excerpt from Lost Hope.