During the time spent in MLP fandom I met the idea of “Elements of Disharmony” for several times. And always they were too similar to their opposites. I mean, why the powers that want to destroy a society and represent various vices will cooperate with each other? Why they, being totally chaotic and destructive, will have any constant avatar, especialy a simple mortal creature? Seriously, I’ve seen Trixie as one of them in some theory. Now let’s delve it the grim darkness of the lands beyond Equestria, where you can find at least pirates, conquerors and slave trade.
 
Soooo, I think you will guess the origin of this concept. The place where these… powers dwell we know as realm of dreams, which seems to be actually a realm, from where Luna’s inner demon tried to escape into reality and where, I suppose, Twilight was alicornized. The second thing is that they more ideas than true gods with names, biographies and other stuff. And this is where they are similar to what we know: things like Tree of Harmony and Crystal Heart took their form just because of their nature, while our evil - as I said - can’t.
 

 
Hate may be familiar to equestria more than others, since because of it they have gathered in their new land. Called the Snow Queen, she sits on an ice throne among the mountains of the Frozen North, where the cold reaches the soul. Her eyes sweetens the picture of primitive hatred - senseless and merciless. The weak die, the strong survive in endless circles of natural selection, driven by cold and fierce competition. No plotting, no unions, no magic - only reckless anger, calling for the extinction.
 
By fate on the borders of the frozen wastes, where life is possible with the greatest difficulty, have their primitive existence of the barbarian tribes. Winter took away their weak and destroyed the fields, and in a whisper of cold wind the leaders of the northerners heard the speech of frosty spirits. Windigo told them that they would save the lives of those who would serve them and bear the winter, taking the weak from the southern lands. Since then, the tribes that have overcome their internal enmity rise together with snow storms and go to the South of the old world, leaving behind desolation and death.