Every villain has a beginning. Are few the creatures in our world which are inherently evil and hurtful. And one of the most infamous villains in the history of Equestria is Cozy Glow.
So young, yet her heart filled with such desire and greed for power that only the appreciation of the Lord of Chaos for the unpredictable can compare.
If she seeks for something, she gets it.
She hid her tracks and manipulated the situation, blaming the others for her crimes. But one day she had an eye bigger than her belly and lost.
Now, defeated, yet filled with hubris for her feats, she decides to tell her history. Because like many other villains, she wasn't born a monster. Like many others villains, she is one because of the world and is the world to blame.