NFE PhysDef Calm Mind (Clefairy) @ Eviolite  
Ability: Magic Guard  
EVs: 252 HP / 252 Def / 4 SpD  
Bold Nature  
IVs: 0 Atk  
- Calm Mind  
- Soft-Boiled  
- Moonblast  
- Stealth Rock / Flamethrower

NFE SpDef Calm Mind (Clefairy) @ Eviolite  
Ability: Magic Guard  
EVs: 252 HP / 4 Def / 252 SpD  
Calm Nature  
IVs: 0 Atk  
- Calm Mind  
- Soft-Boiled  
- Moonblast  
- Stealth Rock / Flamethrower 
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Optional Move(s): 
- Aromatherapy
- Charge Beam
- Cosmic Power
- Knock Off
- Stored Power
- Thunder Wave
- Wish
Optional Item(s): 
- N/A
Optional Ability: 
- N/A
Optional EV/IV(s): 
- 252 HP / 144 Def / 112 SpD (Bold)
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Overview: Clefairy stands out as one of the best all-round Pokemon in the current metagame, combining fantastic utility, great defensive capabilities and a late game win condition all into one Pokemon. 
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PhysDef Calm Mind: Calm Mind boosts Clefairy's special defense, which allows it to keep setting up safely and avoid 2HKOes from the majority of special attackers, including Electabuzz, Frogadier, defensive Roselia and special Combusken after a boost or two. Soft-Boiled provides Clefairy with the longevity it needs to perform its role as a defensive wall and late game cleaner. Moonblast is a fairly strong STAB move, capable of denting Pokemon that don't resist Fairy-type attacks after a few Calm Mind boosts. The fourth moveslot is customizable. Indeed, Clefairy is one of the best Stealth Rock users in the tier due to its fantastic defensive capabilities and longevity. However, Flamethrower can also be valuable as a coverage move on Calm Mind sets if Stealth Rock is not needed, since it lets Clefairy hit Steel-types such as Ferroseed and Pawniard, as well as certain Poison-types such as Roselia for super effective damage. Magic Guard is an exceptional ability on Clefairy, which lets it avoid hazard damage as well as any accumulation of chip from status-inducing moves such as Toxic which would otherwise hinder its defensive and cleaning potential.
This fully physically defensive Clefairy is able to easily take on relatively weak physical attackers such Sliggoo, Krokorok and Gabite. However, it has to watch out for Curse-boosted Iron Tail from Sliggoo and Knock Off from Krokorok.
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SpDef Calm Mind: A specially defensive Calm Mind set gives up physical bulk for additional special bulk, letting Clefairy serve as a much more reliable switch-in to some of the special attackers listed above, but also gives it an easier time switching into and setting up on many boosted special attackers. This includes Choice Specs users such as Electabuzz, Frogadier and Magmar, as well as weak special Pokemon which hit Clefairy for super effective damage but cannot 2HKO it like defensive Roselia and Gloom.
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Checks & Counters: Haze users such as Mareanie and Dusclops hard counter all Clefairy sets. They both can happily switch into any attack and Haze all Calm Mind boosts away. Poison-types such as Roselia, Gloom and Haunter can also switch into Clefairy but will be walled after a Calm Mind boost or two. Steel-types such as Metang and Lairon can easily come in on Clefairy even if the latter is running Flamethrower, and can threaten it out with powerful, super effective Steel-type STAB moves. Specially defensive Servine sets can switch into Clefairy and threaten it with Contrary Leaf Storms, even if Clefairy is boosted. Alolan Grimer can also switch into Clefairy and immediately threaten it with physical Poison-type moves. Taunt users such as Quilladin can shut Clefairy down if specially defensive with Taunt and/or Roar. Encore Kadabra can shut Clefairy down since it can lock Clefairy into a non-attacking move and force it to switch out.
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Optional EV/IV(s): An alternative spread of 252 HP / 144 Def / 112 SpD with a Bold nature is viable for the Cosmic Power, Charge Beam, Stored Power and Soft-Boiled Clefairy set. This set acts as a late-game win condition and the EV spread lets Clefairy avoid the 2HKO from Choice Specs Electabuzz and Life Orb Frogadier Hydro Pump. It also can set up on specially defensive Roselia. On the physical side, it is not 2HKOed by Choice Scarf Staravia. At +1, it can avoid a 2HKO from Heavy Slam Machoke, Metang and Life Orb Frogadier Gunk Shot.
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