My Dearest Rainbow Dash,
It is in my deepest apologies that I say this, but I do not request that you come to the Crystal Empire. It is far too dangerous. However, I wanted to tell you that you are an amazing, brave, and intellegent pegasus. I have faith that you will be alright. Stay strong, my loyal pony. King Sombra and I will be getting married today (I have no say in it), but that does not mean you should lose hope. Never give up, Rainbow Dash. As I have raised the moon all of these years, you will raise the skies. You will be exceptional at everything you do. I am certain of it.
I am proud of you, Rainbow Dash. And I am more than proud to call you my friend.
Yours Truely,
Princess Luna