A re-made form of the mare who is probably my literal oldest character. I've had her in my head ever since I was a very small child first discovering the original My Little Pony movie (which was the first MLP thing I ever watched).
Two things of note about South:
1. She is not an Alicorn. To my way of thinking an Alicorn, both the Show-canon kind and the ones which are seen in the world-canon which South is from, are ponies with equal access to the magic of all three of the main pony tribes (Earth/Pegasi/Unicorn), if not being an outright god/goddess. South only has Pegasi and Unicorn magic, and her Pegasi magic is significantly weaker than her Unicorn magic. In her world, hybrids between the three tribes of pony are actually fairly common, though most don't show it quite as obviously as South does.
2. In-verse, Dark magic is not the same thing as Black magic. Dark magics are those relating to shadows and the night. Black magic is magic which is inherently harmful to yourself or another person. Examples include spells to control another person's body or mind, spells designed specifically to cause pain and things like necromancy.