#0036 · Gen 1

Clefable (Mega) — Best counters

Weaknesses

poison×1.60rock×1.60steel×1.60electric×1.60ice×1.60

	Pokémon	Fast move	Charged move	Weather	Score
1	Regieleki	normalLock On	electricThunder CageELITE	Rainy · partial	10013.3
2	Deoxys (Attack)	poisonPoison Jab	electricZap Cannon	Rainy · partial	9512.6
3	Metagross (Mega)	steelBullet Punch	steelMeteor MashELITE	Snow	8611.5
4	Diancie (Mega)	rockRock Throw	rockRock Slide	Partly Cloudy	8611.5
5	Beedrill (Mega)	poisonPoison Jab	poisonSludge Bomb	Overcast	8411.2
6	Manectric (Mega)	electricThunder Fang	electricWild Charge	Rainy	8211.0
7	Gengar (Mega)	ghostLickELITE	poisonSludge Bomb	Overcast · partial	8110.8
8	Xurkitree	electricThunder Shock	electricDischarge	Rainy	8110.8
9	Kyurem (White)	iceIce Fang	iceBlizzard	Snow	8110.8
10	Ampharos (Mega)	electricVolt Switch	electricZap Cannon	Rainy	7910.5
11	Zekrom	electricCharge Beam	electricFusion BoltELITE	Rainy	7810.3
12	Eternatus	poisonPoison Jab	poisonSludge Bomb	Overcast	7710.2
13	Tyranitar (Mega)	rockSmack DownELITE	rockStone Edge	Partly Cloudy	7610.2
14	Metagross	steelBullet Punch	steelMeteor MashELITE	Snow	749.9
15	Zacian (Crowned)	steelMetal Claw	normalGiga Impact	Partly Cloudy · partial	749.9
16	Aerodactyl (Mega)	rockRock Throw	rockRock Slide	Partly Cloudy	749.8
17	Naganadel	poisonPoison Jab	poisonSludge Bomb	Overcast	739.7
18	Rampardos	rockSmack Down	rockRock Slide	Partly Cloudy	729.7
19	Thundurus (Therian)	electricVolt Switch	electricThunderbolt	Rainy	729.6
20	Lucario (Mega)	steelBullet Punch	steelFlash Cannon	Snow	719.5

Clefable (Mega) is weak to Poison (×1.6), Rock (×1.6), Steel (×1.6), Electric (×1.6), Ice (×1.6).
Rainy weather boosts Electric moves ×1.2 — the best time to battle Clefable (Mega).

Rankings are estimated cycle DPS (attack stat × move damage ÷ cycle time, with STAB and type effectiveness). Not a full battle simulation.