Malachite appeared in a flash of inspiration at about that time. So many things just came together all of a sudden. The concept of otherworldly faeries and a hivelike creature all came together, and I realized that it was a pony, a former student of Celestia, who was going to be the antagonist of the Equestrian side of things. I didn't plan it. Malachite sprung into my mind, almost completely formed, just needing a few details fleshed out. 