This seems super unfair, but if Kyurem EX uses Hail Blizzard and can't use the attack the next turn, it shouldn't matter whether or not you switch him out then back in next turn, correct? Or if you switch him to the bench then active in a single turn, does it erase the effect so that you can spam Hail Blizzard multiple times in a row? If so, it seems like a pretty broken rule.