"Because I don't dare to return to Equestria," Malachite said, with complete honesty. "At least, not at this time. Here on Earth, I can match, or even defeat the Princesses. I designed my body with that in mind. As long as they can't draw directly on the magic of Equestria, I can stave them off. However, on Equestrian soil, I wouldn't stand a chance. And, simply, I don't trust them not to immediately imprison me, or perhaps execute me." 