Kyurem (Hasty/Naive nature; either one works)
Item: Red Card
EV spread: 100 Attk, 156 Sp.Attk, 252 Speed OR 252 Sp.Attk, 252 Speed, 4 Attk.
Moves: Hone Claws
This set aims to utilize Kyurem's awesome high-base power attacking moves while removing that pitiful accuracy problem. Set up Hone claws as they switch out, only to have them attack and get forced out with Red Card (which, depending on the situation, may give you two attack and accuracy boosts). From there, obliterate everything with Blizzard. Focus Blast is for steels, and Outrage is to prevent Blissey from having an opportunity to come in on you.
The EVs depend on how strong you'd like Outrage to be after a Hone Claws boost. In my first version, I treat it as more of a mixed sweeper with its 100 Attack EVs and 156 Sp. Attk EVs. The second set treats Kyurem as more of a special sweeper with Outrage to top things off. Speed is obvious in both sets.