Counter that Pokémon

[Jin Of The Gale]

Darmanitan (F) @ Lum Berry
Trait: Sheer Force
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Flare Blitz
- Earthquake
- Rock Slide
- Superpower

252+ Atk Sheer Force Darmanitan Flare Blitz vs. 200 HP / 64 Def Jirachi: 554-654 (141.6 - 167.2%) -- guaranteed OHKO

It can switch into Thunder Wave, get its status ailment removed using Lum Berry and OHKO in the next turn.

244+ Atk Jirachi Iron Head vs. 0 HP / 0 Def Darmanitan: 96-114 (27.3 - 32.4%) -- guaranteed 4HKO

 

[Nah]

-Slowbro w/Leftovers
Nature: Bold
Ability: Regenerator
EVs: 248 HP, 244 Defense, 16 Sp.Attack
Moves: Scald, Psyshock, Slack Off, Fire Blast

Slowbro can take Flare Blitz and Superpower no problem, and probably not that much from Earthquake and Rock Slide. From there, its just some Scald and Slack Off till Darmanitan is dead.

 

[Jin Of The Gale]

Hydreigon @ Life Orb
Ability: Levitate
EVs: 252 SAtk / 252 Spd / 4 HP
Modest Nature
- Fire Blast
- Draco Meteor
- Focus Blast
- Dark Pulse

 

[Dark Azelf]

-Slowbro w/Leftovers
Nature: Bold
Ability: Regenerator
EVs: 248 HP, 244 Defense, 16 Sp.Attack
Moves: Scald, Psyshock, Slack Off, Fire Blast

Slowbro can take Flare Blitz and Superpower no problem, and probably not that much from Earthquake and Rock Slide. From there, its just some Scald and Slack Off till Darmanitan is dead.

Vaporeon@Leftovers
252 HP / 252 Def / 6 Sp.Def
Bold Nature
Trait: Water Absorb
- Scald
- Toxic
- Wish
- Protect

Takes basically nothing from all of Slowbro's attacks and can then Toxic, Wish and Protect until its dead.

 

[Hiatus]

Breloom w/ Toxic Orb
Nature: Adamant
Ability: Poison Heal
12 HP / 252 Atk / 244 Spe
~ Spore
~ Substitute
~ Focus Punch
~ Seed Bomb

Toxic Orb would activate as soon as Breloom switches in, preventing it from getting burned with Scald. After that, it'd put Vaporeon to sleep with Spore, set up Substitute, then Seed Bomb its way.

 

[Dark Azelf]

Breloom w/ Toxic Orb
Nature: Adamant
Ability: Poison Heal
12 HP / 252 Atk / 244 Spe
~ Spore
~ Substitute
~ Focus Punch
~ Seed Bomb

Toxic Orb would activate as soon as Breloom switches in, preventing it from getting burned with Scald. After that, it'd put Vaporeon to sleep with Spore, set up Substitute, then Seed Bomb its way.

Toxic Orb doesnt activate as soon as it switches in, Scald can still burn as Loom switches in and if that happens Breloom loses iirc.

Anyways;

Trevenent@Leftovers
252 HP / 216 Def / 40 Sp.Def
Trait: Natural Cure
Impish Nature
- Leech Seed
- Rest
- Will-O-Wisp
- Shadow Claw

Hard walls Breloom as it cannot do anything to it, including Spore.

 

[Nah]

-Volcarona w/Life Orb
Nature: Modest
Ability: Flame Body
EVs: 252 Sp.Attack, 252 Speed, 4 Defense
Moves: Fiery Dance, Bug Buzz, Quiver Dance, Giga Drain

Volcarona can take a couple of Shadow Claws from Trevenant:

0 Atk Trevenant Shadow Claw vs. 0 HP / 4 Def Volcarona: 117-138 (37.6 - 44.3%) -- guaranteed 3HKO

It doesn't care about Will-o-Wisp, and can OHKO with Fiery Dance:

252+ SpA Life Orb Volcarona Fiery Dance vs. 252 HP / 40 SpD Trevenant: 432-510 (115.5 - 136.3%) -- guaranteed OHKO

Finally bothered to look for a Gen 6 damage calculator.

 

[SkySpoon]

Infernape (M) @ Choice Band
Trait: Iron Fist
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Stone Edge
- Thunder Punch
- Close Combat
- Flare Blitz

252+ SpA Life Orb Volcarona Fiery Dance vs. 0 HP / 0 SpD Infernape: 126-149 (43 - 50.8%) -- 3.9% chance to 2HKO
+1 252+ SpA Life Orb Volcarona Fiery Dance vs. 0 HP / 0 SpD Infernape: 191-225 (65.1 - 76.7%) -- guaranteed 2HKO
Don't think I need to calc stone edge

 

[Aeroblast]

Hippowdon @ Leftovers
Sand Stream
EVs: 252 HP / 252 Def / 6 SpD
Impish Nature
-Earthquake
-Ice Fang
-Slack Off
-Stealth Rock

Can take a Flare Blitz/Close Combat or two, then OHKOs back with Earthquake.

 

[Jin Of The Gale]

Articuno @ Life Orb
Trait: Pressure
EVs: 252 SAtk / 4 SDef / 252 Spd
Modest Nature (+SAtk, -Atk)
- Ice Beam
- Hurricane
- Roost
- Substitute

252+ SpA Life Orb Articuno Ice Beam vs. 252 HP / 6 SpD Hippowdon: 439-523 (104.5 - 124.5%) -- guaranteed OHKO

 

[WinterKirby]

Specially defensive Crustle can safely switch in to both Hurricane and Ice Beam. Articuno is also severely weak to Stealth Rock, losing 50% of its health and rendering Roost useless. Rock Blast breaks through Substitute without a hitch.

0 Atk Crustle Rock Blast (2 hits) vs. 0 HP / 0 Def Articuno: 216-264 (67.2 - 82.2%) -- guaranteed OHKO after Stealth Rock
0 Atk Crustle Rock Blast (3 hits) vs. 0 HP / 0 Def Articuno: 324-396 (100.9 - 123.3%) -- guaranteed OHKO after Stealth Rock
0 Atk Crustle Rock Blast (4 hits) vs. 0 HP / 0 Def Articuno: 432-528 (134.5 - 164.4%) -- guaranteed OHKO after Stealth Rock
0 Atk Crustle Rock Blast (5 hits) vs. 0 HP / 0 Def Articuno: 540-660 (168.2 - 205.6%) -- guaranteed OHKO after Stealth Rock

Crustle @ Leftovers
Ability: Sturdy
EVs: 240 SDef / 252 HP / 16 Def
Careful Nature
- Spikes
- Stealth Rock
- Rock Blast
- X-Scissor

 

[Nah]

-Aggron w/Air Balloon
Nature: Adamant
Ability: Rock Head
EVs: 252 Attack, 252 Speed, 4 HP
Moves: Head Smash, Earthquake, Automotize, Iron Head


Aggron's skull says hi.

 

[Jin Of The Gale]

I wouldn't call Crustle a good counter. Unless you're relying on Hurricane's 30% chance to miss, Articuno will 2HKO Crustle.

252+ SpA Life Orb Articuno Hurricane vs. 252 HP / 240+ SpD Crustle: 181-214 (52.6 - 62.2%) -- guaranteed 2HKO
252+ SpA Life Orb Articuno Ice Beam vs. 252 HP / 240+ SpD Crustle: 148-175 (43 - 50.8%) -- 4.3% chance to 2HKO

Spoiler:

Start of turn 1
The Lion Heart called Smeargle back!
The Lion Heart sent out Crustle!

Articuno used Hurricane!
The foe's Crustle lost 59% of its health!
Articuno is hurt by its Life Orb!

The foe's Crustle restored a little HP using its Leftovers!

Start of turn 2
Articuno used Ice Beam!
The foe's Crustle lost 46% of its health!
The foe's Crustle fainted!
Articuno is hurt by its Life Orb!

Anyway

Quagsire (M) @ Leftovers
Trait: Unaware
EVs: 248 HP / 252 Def / 8 SDef
Relaxed Nature (+Def, -Spd)
- Recover
- Counter
- Earthquake
- Scald

252+ Atk Aggron Head Smash vs. 248 HP / 252+ Def Quagsire: 96-113 (24.4 - 28.7%) -- possible 5HKO after Leftovers recovery
252+ Atk Aggron Earthquake vs. 248 HP / 252+ Def Quagsire: 85-101 (21.6 - 25.6%) -- possible 5HKO after Leftovers recovery

0 SpA Quagsire Scald vs. 4 HP / 0 SpD Aggron: 186-218 (65.9 - 77.3%) -- guaranteed 2HKO

 

[Aeroblast]

Venusaur @ Venusaurite
Ability: Thick Fat
IVs: 252 HP / 252 SpAtk / 4 SpDef
Nature: Modest
- Synthesis
- Giga Drain
- Sludge Bomb
- Hidden Power Fire

Don't think I need to calc.

 

[Shizzable]

Talonflame @ Life Orb
Ability: Thick Fat
EVs: 124 HP / 252 Atk / 132 Spd
Adamant Nature
- Brave Bird
- Flare Blitz
- Roost
- Swords Dance

Sludge Bomb will hurt a lot, but Talonflame's Brave Bird will destroy Venusaur no matter what.

 

[Jet Pilot]

Cinccino @ Choice Band
Ability: Skill Link
Nature: Adamant
EVs: 252 Atk / 252 Spe / 4 HP
- Rock Blast
- Bullet Seed
- Tail Slap
- U-Turn

Talon would OHKO w/ Brave Bird although with the way your EVs are spread, my Cinccino outspeeds your Talon by 8 points. Rock Blast is a guaranteed 200% even w/o Life Orb/Choice Band.

Needed to use Calc for this, as Talon's speed is beastly.

Last I remember it said no unreleased DW abilities, I don't quite know what that means. Even with Technician Cin would KO Talon.
Calc:

Spoiler:

252+ Atk Choice Band Cinccino Rock Blast (5 hits) vs. 124 HP / 0 Def Talonflame: 980-1160 (298.7 - 353.6%) -- guaranteed OHKO

 

[PlatinumDude]

Cinccino @ Choice Band
Ability: Skill Link
Nature: Adamant
EVs: 252 Atk / 252 Spe / 4 HP
- Rock Blast
- Bullet Seed
- Tail Slap
- U-Turn

Talon would OHKO w/ Brave Bird although with the way your EVs are spread, my Cinccino outspeeds your Talon by 8 points. Rock Blast is a guaranteed 200% even w/o Life Orb/Choice Band.

Needed to use Calc for this, as Talon's speed is beastly.

Last I remember it said no unreleased DW abilities, I don't quite know what that means. Even with Technician Cin would KO Talon.
Calc:

Spoiler:

252+ Atk Choice Band Cinccino Rock Blast (5 hits) vs. 124 HP / 0 Def Talonflame: 980-1160 (298.7 - 353.6%) -- guaranteed OHKO

Just saying, Cinccino can't switch in on Talonflame, and even if it did, priority from a boosted Brave Bird can take it out. Also, Skill Link Cinccino is available because Minccino is a Friend Safari Pokemon.

Anyway:

Aggron:

-Rest
-Sleep Talk
-Heavy Slam/Iron Head
-Earthquake
Nature: Impish
EVs: 252 HP/4 Def/252 SDef
Item: Aggronite
Ability: Sturdy

Mega Aggron takes almost nothing from Cinccino at all, while retaliating with Heavy Slam or Iron Head.

 

[Shizzable]

Hydreigon @ Choice Specs
Ability: Levitate
Nature: Modest
EVs: 4 HP / 252 SpA / 252 Spe
- Draco Meteor
- Focus Blast
- Flamethrower
- Dark Pulse

"Hydreigon belongs to the special group of Pokemon that can boast they possess no true counters" -Smogon

...inb4 Fairies :(

 

[PlatinumDude]

Hydreigon @ Choice Specs
Ability: Levitate
Nature: Modest
EVs: 4 HP / 252 SpA / 252 Spe
- Draco Meteor
- Focus Blast
- Flamethrower
- Dark Pulse

"Hydreigon belongs to the special group of Pokemon that can boast they possess no true counters" -Smogon

...inb4 Fairies :(

Not true this gen.

Azumarill:

-Aqua Jet
-Play Rough
-Superpower
-Waterfall/Return
Nature: Adamant
EVs: 212 HP/252 Atk/44 Spe
Item: Choice Band
Ability: Huge Power

Walls Hydreigon with its immunity to Fairy and resistance to everything else it has, then wrecks it with Play Rough.

 

[Nah]

-Amoonguss w/Black Sludge
Nature: Bold
Ability: Regenerator
EVs: 252 HP, 252 Defense, 4 Sp.Attack
Moves: Spore, Giga Drain, Sludge Bomb, Hidden Power Fire

Azumarill can only 4HKO this Amoonguss:

252+ Atk Choice Band Huge Power Azumarill Waterfall vs. 252 HP / 252+ Def Amoonguss: 107-126 (24.7 - 29.1%) -- possible 5HKO after Black Sludge recovery
252+ Atk Choice Band Huge Power Azumarill Play Rough vs. 252 HP / 252+ Def Amoonguss: 120-142 (27.7 - 32.8%) -- 81.3% chance to 4HKO after Black Sludge recovery

Amoonguss can then use Giga Drain to kill Azumarill while healing the damage it takes.