" Ahhhhhh, dont we look beautiful like this sister ?" "Hey who said that?" "Its me the flames that make up our mane. Our other sister should be waking up now." "Ahhhhh its good to be free. I can see that our new sister is confused we should tell her about the 3 of us." "Good idea. You see Twilight my sister and I are fire elementals. We normally only apear as flames." "But if we discover a filly that can hold and merge with us we enter her body and bind our souls to hers." " We did this with you years ago, when you took the entrance exam at the school. Your magical outburst brought us to you. Usualy we just bind ourselves to whoever called us, but when we enterd your body instead of binding our souls completly merged with yours." "You were to young for us to manifest, so we slept untill you were old enough for us to emerge. My older sister became our mane. And I became our tale. Now that the 3 of us have shed our old look, we are now more than just body/soul mates. Together"We are sisters, lovers and wive's. If we try to seperate, the shock whould kill us, our souls are so intertwined. And as long as we stay true to eachother we can never die or grow old."
That's actually a character for a fanfic I'm writing. The idea came from when Twily gets mad in the series and goes all Flame On and I wanted to explore the idea that maybe there was something more to that than just a visual gag.