Going to add to this mon by saying that 3a CM Clef is a ridiculously strong mon. I've used it on Sticky Webs to varying success and it always ends up catching people out on its unexpectedly decent speed tier.Calm Mind Clefable is vastly underutilized. LO+3 and Defensive seem to be mostly what are run now but CM should really be used more.
Clefable @ Life Orb
Ability: Magic Guard
EVs: 4 HP / 252 SpA / 252 Spe
Modest Nature
IVs: 0 Atk
- Calm Mind
- Moonblast
- Thunderbolt
- Moonlight
I know, I know. No fire move. But who are the main steel types in OU that can switch in and threaten Clef? Ferro, Aegislash, and Exca. Just run mons that lure and burn ferro and it can't do anything to you, even if it has gyro. Excadrill can be hard walled by a Corviknight on your team and can't switch into moonblast repeatedly since it is 3HKOd. Aegislash varies on the set but won't be keeping Clef away for very long since it will fall to 3 thunderbolts if it is not invested.
Many of the Clef checks like rotom, defensive clef, or sylveon rely on LO clef not being able to break them but they can just be boosted past with calm mind. It puts immense pressure on teams since it destroys slower cores, is immune to poison and hazards, and is very hard for offense to switch into. It's also very difficult to KO when boosted due to having very few weaknesses.
Clefable @ Life Orb
Ability: Magic Guard
EVs: 4 Def / 252 SpA / 252 Spe
Timid / Modest Nature
- Moonblast
- Fire Blast
- Psychic / Thunderbolt
- Calm Mind
The following set has very little in the way of defensive counterplay - not only are mons such as Ferrothorn, Excadrill, Aegislash and Corviknight all 2HKO'd by Fire Blast, Rotom-Heat is also taken out by a Calm Mind on the switch - the only way that Rotom-H can reliably beat Clefable is by Volt Switching out of it into another teammate that can threaten it out, such as Excadrill. The issue with this comes with how well Sticky Webs enhance Clefable's wallbreaking capabilities: once checks / counters to Clefable (with the only exception being Cinderace, as a check (it is sometimes 2HKO'd by Psychic / Thunderbolt) simply cannot deal with a Fire Blast coming their way. CM Clef also ends up breaking generally SpDef walls, since often times with Moonlight Clefable you'll end up fighting a losing battle with another Clefable - in this case, CM Clefable takes minimal damage from the SpDef Fairy (25.6% worst case assuming no Moonblast SpA drops). This can end up being quite a boon when paired with a breaker such as Dragapult or Hydreigon.