Yes, the disc is hard to follow, but snazzy moves will get him nowhere unless he can hit her. Once it comes close to her, the disc bounces off that invisible wall of hers. The shield still holds.

Meanwhile Dairine keeps charging foward, but at the last minute feigns to the side. As she moves, she uses the disc in her hand to slice upward, aiming at Rinzler's torso. Larger part, bigger target. Maybe she can score a lucky hit.