Dear Twilight Sparkle:
Do you have any idea how my people have struggled to survive for such a long time?! This invasion was nothing less than my reclaiming what was rightfully ours! Don't you call me a bitch or evil, because the only pony you're describing is yourself.
You see, it all began hundreds of years ago, when Celestia attempted to unite the many pony tribes under her iron hoof. My ancestors, the first members of the changeling royal family, refused to be swayed by her empty promises of love and tolerance, and so we rebelled in an attempt to create a true egalitarian society, flowing with the love we needed to sustain ourselves.
As you may be aware, the Solar Tyrant was enraged by this perceived treachery, and so she led her warriors to destroy our towns and hives and slaughter our families. Only a few of us survived the holocaust, our plans for a peaceful existence crushed by the Troll Daughter. Reduced to feeding on meager scraps of love, we slowly but surely began to plot our revenge. A few of us were able to infiltrate the government, transforming the crystal mines into a perfect prison before having them abandoned, then convincing Celestia to leave the elements out of anypony's reach but hers.
Also, "Department of Equestrian Security"? Don't be silly. Not even the Diamond Dogs would be stupid enough to do something so profoundly idiotic. Although those bald apes that Celestia exterminated might have had similar bad ideas.
But I'm getting off topic. After some trial and error we identified the perfect target: the Princess of Sex, Cadance Notevil Goodpony. As it turns out, her good heart ended up being her undoing; she was so determined to help those poor foals trapped in the mine that she didn't sense the trap we had set until it was too late. This left an empty place next to the groom which I was able to appropriate, thus ensuring that I'd have a perfect shot at killing the Troll Daughter.
Unfortunately, you had to get in our way. At first I decided to send you into the mines, hoping that you'd be so enraged that you'd kill her for me, saving me a big pain in the ass later on. Even if you didn't, I believed your selfishness would prevent you from lifting a hoof to help her. Unfortunately, the Sex Goddess just had to promise you a threesome with your testosterone-factory of a brother. Damn.
Fortunately, when I was forced to reveal myself, I discovered that the Solar Tyrant is not as powerful as she had been a thousand years ago. Apparently ten centuries of eating cake can be a severe liability for one's level of power. And ultimately my soldiers were able to capture you and your friends, thus proving that the tyranny of ponies will always be overcome by the love and unity that we changelings share with each other.
Or, at least until you managed to release the Sex Goddess from her bonds. I must admit, I was quite impressed by how she was able to combine her love with Shining Armor's power to throw us all out. Even so, I feel disgraced, for I have failed my people and my ancestors in failing to take back our home.
I suppose now you're going to force your brother to go through with his wife's threesome promise or something. I must gather my troops so we can create a new plan to reclaim our promised land.
Your disappointed invader, Chrysalis, Queen of the Changelings.
Dear Twily:
...Did she really promise that?
Your very worried brother, Shining Armor.