Is the Kyurem you use the Outrage one, or the Plasma one? Either way, you unfortunately lose a lot post-rotation (assuming XY-on) given that Jirachi EX, Mewtwo EX, both types of Kyurem, all ACE Specs, Max Potion, N, Colress & Skyla all go away. At present, it's hard to say what will be good...