Kyurem has been lightly touched upon, but I feel it needs a bit more recognition, especially Kyurem in the Hail (The only reason to use Hail tbh). SubRoost Kyurem is a very strong pokemon, having huge attack, amazing bulk, instant recovery, and decent enough speed. What makes him really great is his ability Pressure. Pressure allows Kyurem to stall out many low PP moves such as Gyro Ball, Hydro Pump, Stone Edge, and even Focus Blast if the user in question is slower than Kyurem. Blizzard + Earth Power have amazing coverage together. Ice+Dragon is actually a decent enough typing if only for that Dragon-type (although neutrality to Ice is pretty awesome). Bad part about the typing is weakness to SR, which Roost can recover. Roost is really good on Kyurem, since he has good bulk and decent speed, allowing him to recover SR and Substitute damage. The only problem Kyurem has is that it can't do much to Water-types. Oh, what's that? His best friend Abomasnow completely destroys Water-types? Oh, ok! Speaking of Abomasnow, he can be pretty devastating with a Sub as well, as Leech Seed + Hail Damage adds up quickly. Not only that, but only Ice-types aren't affected by Hail, which is an uncommon type for pokemon to carry in the Meta. He can also fire off strong Giga Drains or even Hammer Arms to destroy Water-types, and has Ice Shard to hit Dragons. Seriously, SubRoost Kyurem is a huge threat, and I definitely recommend using it (FB + DPulse doesn't seem bad either, dat neutral coverage)