I didn't know that Blizzard had 100% accuracy in Hail? Does sandstorm also give some benefit aswell? anyways, I'm glad you liked some of my suggestions! I researched that both Glalie and Walrein have the ability Ice Body which heals them during hail. I would personally go with Walrein due to his decent defenses and great attack and special attack. It naturally learns Blizzard so if the information above is correct it gets 100% accuracy. It also eliminates fire and rock weaknesses with water attacks (many steel types are also part rock or part ground. Maybe experiment with Waterfall instead of Surf to protect your team, especially Mamoswine). Abomasnow is good aswell, but be cautious about his fire weakness. He also has grasswhistle which can be effective in putting annoying foes to sleep. If you're looking for someone who's not ice, put leftovers on them so the hail's damage is nullified. Swampert, Quagsire and Gastrodon would be good choices because Muddy Water attacks two foes at once without hurting your teammates, has a chance of lowering foes accuracy, and their grass weakness is easily covered by your teams' devastating Ice attacks. Blastoise can also learn Muddy water by breeding. Sorry I'm typing alot, but I hope I'm helping you out. If you ever want to test your team, give me a shout and we can battle.