These attacks all had one major flaw -- they came from the front. (Okay, technically Marvelous's came from above, but she still saw it coming.) Celestia planted all four hooves powerfully, then tossed her head back. A spherical shield grew around her, a spell she'd grown much more proficient in thanks to being able to study Shining Armor's. As rocks and fire and electrical needles clattered off it, Celestia poured more power into it, expanding it in a burst that transformed it from shield to shockwave, the better to sweep everyone off their feet and slam them into walls.