Unicorns have always considered themselves to be superior to Earth Ponies. They are much better at their jobs, they can preform magic, and are overall smarter than Earth ponies. But there's no HATE between Unicorns and Earth Ponies, right?
And that HATE would never cause a pony to kill another pony, right? Especially if those ponies are best friends...
right?

(warning may be offensive to some viewers)