Weavile should use Low Kick over Brick Break so that it can hit heavier opponents harder; Brick Break's power may not be enough, considering that the majority of Rocks and Steels are rather heavy. The EV spread should be 32 HP/252 Atk/224 Spe, which is just enough to outspeed Therian Tornadus.
Kyurem is a better option over Froslass, IMO, because Froslass is more of a support mon, while Kyurem is more of an all-out attacker:
-Substitute
-Roost
-Blizzard/Dragon Pulse
-Earth Power/Focus Blast
Nature: Modest
EVs: 52 HP/220 SAtk/236 Spe
Item: Leftovers
or
-Draco Meteor
-Blizzard
-Earth Power
-Focus Blast
Nature: Timid/Modest
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Specs/Choice Scarf
or
-Draco Meteor
-Blizzard
-Focus Blast/Earth Power
-Roost/Earth Power
Nature: Timid/Modest
EVs: 32 HP/252 SAtk/224 Spe
Item: Life Orb
or
-Draco Meteor
-Blizzard
-Earth Power
-Outrage
Nature: Mild/Hasty
EVs: 32 Atk/252 SAtk/224 Spe
Item: Life Orb
Hail teams have a tendency to be weak to Stealth Rock, as well as Fire moves. Heatran is a good check to Fire Pokemon, thanks to Flash Fire, while Forretress can Rapid Spin away entry hazards.
Heatran:
-Lava Plume
-Stealth Rock
-Will-o-Wisp/Toxic
-Protect
Nature: Calm
EVs: 248 HP/252 SDef/8 Spe
Item: Leftovers
Ability: Flash Fire
or
-Fire Blast
-Earth Power
-Hidden Power (Ice/Grass)
-Stealth Rock/Taunt/Flame Charge
Nature: Timid/Modest
EVs: 252 SAtk/4 SDef/252 Spe
Item: Life Orb/Air Balloon
Ability: Flash Fire
or
-Overheat
-Flamethrower
-Earth Power
-Hidden Power (Ice)/Dragon Pulse
Nature: Timid/Modest
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Scarf
Ability: Flash Fire
or
-Overheat/Fire Blast
-Flamethrower/Hidden Power (Grass)
-Earth Power
-Dragon Pulse
Nature: Modest/Timid
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Specs
or
-Substitute
-Torment
-Protect
-Lava Plume
Nature: Calm
EVs: 244 HP/44 SDef/220 Spe
Item: Leftovers
Ability: Flash Fire
Forretress:
-Spikes
-Toxic Spikes
-Rapid Spin
-Gyro Ball/Earthquake/Volt Switch
Nature: Relaxed/Sassy
EVs: 252 HP/176 Def/80 SDef or 252 HP/4 Def/252 SDef
Item: Leftovers/Shed Shell
Ability: Sturdy