A pegasus and an earth pony move to the Everfree Forest after Twilight defeats Trixie for a second time. Begins on the episode Spike is attacked by Timberwolves.
These lovable twins like going at each other's throats. Based on me and my sister. (No I am not a twin).
Oh Yeah did I mention that this was inspired epiphany-like. I was thinking why Celestia only has a unicorn apprentice. Then I think about why she always says twilight is her *best* student. Then it hits me she has other pupils. So why keep them a secret from Twilight. Well, they aren't like other ponies.