Is Mewtwo-Mega-Y viable in Gen 9 National Dex Ubers?

Mewtwo-Mega-Y is ranked #23 in Gen 9 National Dex Ubers with 6.78% usage according to Smogon Jul 2026 - Sep 2026 data.

What beats Mewtwo-Mega-Y in Gen 9 National Dex Ubers?

Yveltal has the strongest conservative score in this observed Jul 2026 - Sep 2026 sample. The target was knocked out or switched out in 75.3% of 187.71116716791195 relevant encounters. Standard error is 3.1 points. Sets and switch conditions can change the result.

How are Mewtwo-Mega-Y matchup checks ranked in Gen 9 National Dex Ubers?

They are ranked by p minus four standard errors. Here, p is the observed fraction of relevant encounters where Mewtwo-Mega-Y was knocked out or switched out. This is not a set-specific battle guarantee.

Mewtwo-Mega-Y counters

Gen 9 National Dex Ubers · Smogon source period Jul 2026 - Sep 2026

#0150 Mewtwo-Mega-Y

Psychic

USAGE 6.8% #23

ABILITYInsomnia

BASE STATS

HP 106

ATK 150

DEF 70

SPA 194

SPD 120

SPE 140

BST780

TYPE MATCHUPS

2×

BugGhostDark

½×

FightingPsychic

Moves

Psystrike 97.8% Nasty Plot 86.2% Ice Beam 81.7% Earth Power 41.9% Fire Blast 24.3% Focus Blast 17.0% Aura Sphere 9.9% Shadow Ball 8.9%

Items

Mewtwonite Y 100.0%

Abilities

Insomnia100.0%

Common Teammates

Browse Gen 9 National Dex Ubers teams using Mewtwo-Mega-Y →

Explore Mewtwo-Mega-Y + Yveltal teams 63 score Explore Mewtwo-Mega-Y + Marshadow teams 59 score Explore Mewtwo-Mega-Y + Zacian-Crowned teams 58 score Explore Mewtwo-Mega-Y + Necrozma-Dusk-Mane teams 35 score Explore Mewtwo-Mega-Y + Arceus-Dark teams 19 score Explore Mewtwo-Mega-Y + Groudon-Primal teams 18 score

Leading observed checks

Open a matchup for a separate set-based damage estimate, or browse uploaded teams with both Pokémon.

Team core to explore

Mewtwo-Mega-Y + Groudon-Primal 69.7% teammate usage Explore teams →

Checks & Counters

Observed target KO or switch rate is upstream p: the fraction of relevant encounters where the target was knocked out or switched out. Standard error is upstream d. The conservative score is p − 4d. These ladder observations do not prove a set-specific counter.

How to read this table

Use encounter count and standard error to judge the sample. Damage estimates below use inferred sets and remain separate from the observed ladder metric.

# Checker Encounters Conservative score Target KO or switch rate

Yveltal

DarkFlying OFFENSIVE CHECK View matchup

187.711

62.8

75.3% Standard error 3.15 points

DAMAGE CALC

0- Atk Life Orb Dark Aura Yveltal Foul Play vs. 252 HP / 0 Def Mewtwo-Mega-Y: 603-712 (144.9 - 171.1%) -- guaranteed OHKO

View Yveltal counters → Teams with Yveltal →

Marshadow

FightingGhost OFFENSIVE CHECK View matchup

43.997

58.7

81.9% Standard error 5.80 points

DAMAGE CALC

252+ Atk Marshadow Poltergeist vs. 252 HP / 0 Def Mewtwo-Mega-Y: 516-608 (124 - 146.1%) -- guaranteed OHKO

View Marshadow counters → Teams with Marshadow →

Zacian-Crowned

FairySteel OFFENSIVE CHECK View matchup

131.476

58.4

73.8% Standard error 3.84 points

DAMAGE CALC

+1 252+ Atk Zacian-Crowned Play Rough vs. 252 HP / 0 Def Mewtwo-Mega-Y: 361-426 (86.7 - 102.4%) -- 18.8% chance to OHKO

View Zacian-Crowned counters → Teams with Zacian-Crowned →

Necrozma-Dusk-Mane

PsychicSteel OFFENSIVE CHECK View matchup

80.439

35.1

57.2% Standard error 5.52 points

DAMAGE CALC

0- Atk Necrozma-Dusk-Mane Sunsteel Strike vs. 252 HP / 0 Def Mewtwo-Mega-Y: 193-228 (46.3 - 54.8%) -- 59% chance to 2HKO

View Necrozma-Dusk-Mane counters → Teams with Necrozma-Dusk-Mane →

Arceus-Dark

Dark DEFENSIVE CHECK View matchup

21.616

18.9

60.8% Standard error 10.50 points

DAMAGE CALC

252+ SpA Mewtwo-Mega-Y Focus Blast vs. 252 HP / 252+ SpD Arceus-Dark: 248-292 (55.8 - 65.7%) -- guaranteed 2HKO

View Arceus-Dark counters → Teams with Arceus-Dark →

Groudon-Primal

GroundFire SOFT CHECK View matchup

137.085

17.7

33.9% Standard error 4.04 points

DAMAGE CALCHarsh Sunshine

252+ Atk Groudon-Primal Heat Crash (120 BP) vs. 252 HP / 0 Def Mewtwo-Mega-Y in Harsh Sunshine: 553-652 (132.9 - 156.7%) -- guaranteed OHKO

View Groudon-Primal counters → Teams with Groudon-Primal →

Zygarde

DragonGround SOFT CHECK View matchup

117.072

12.2

29.0% Standard error 4.19 points

DAMAGE CALC

252+ Atk Zygarde Thousand Arrows vs. 252 HP / 0 Def Mewtwo-Mega-Y: 180-213 (43.2 - 51.2%) -- 5.1% chance to 2HKO

View Zygarde counters → Teams with Zygarde →

Ho-Oh

FireFlying SOFT CHECK View matchup

138.124

11.0

25.9% Standard error 3.73 points

DAMAGE CALC

252+ Atk Ho-Oh Brave Bird vs. 252 HP / 0 Def Mewtwo-Mega-Y: 288-340 (69.2 - 81.7%) -- guaranteed 2HKO

View Ho-Oh counters → Teams with Ho-Oh →

Kyogre-Primal

Water SOFT CHECK View matchup

57.91

3.6

26.9% Standard error 5.83 points

DAMAGE CALCHeavy Rain

252+ SpA Kyogre-Primal Water Spout (150 BP) vs. 252 HP / 252+ SpD Mewtwo-Mega-Y in Heavy Rain: 328-387 (78.8 - 93%) -- guaranteed 2HKO

View Kyogre-Primal counters →

Eternatus

PoisonDragon SOFT CHECK View matchup

53.244

-5.2

13.7% Standard error 4.71 points

DAMAGE CALC

252+ SpA Eternatus Draco Meteor vs. 252 HP / 252+ SpD Mewtwo-Mega-Y: 160-190 (38.4 - 45.6%) -- guaranteed 3HKO

View Eternatus counters → Teams with Eternatus →

Giratina-Origin

GhostDragon SOFT CHECK View matchup

21.491

-6.3

34.7% Standard error 10.27 points

DAMAGE CALC

0- Atk Griseous Core Giratina-Origin Poltergeist vs. 252 HP / 0 Def Mewtwo-Mega-Y: 402-474 (96.6 - 113.9%) -- 81.3% chance to OHKO

View Giratina-Origin counters → Teams with Giratina-Origin →

Arceus-Ground

Ground SOFT CHECK View matchup

41.257

-8.4

11.5% Standard error 4.96 points

DAMAGE CALC

0- Atk Earth Plate Arceus-Ground Earthquake vs. 252 HP / 0 Def Mewtwo-Mega-Y: 183-216 (43.9 - 51.9%) -- 10.9% chance to 2HKO

View Arceus-Ground counters → Teams with Arceus-Ground →

Ranked #23 with 6.78% usage. Sorted by conservative score.