Mega Mewtwo Y
Psychic · 780 BST · Mewtwonite Y
| Stat | Base | Mega | Relative size | Change |
|---|---|---|---|---|
| HP | 106 | 106 | — | |
| Attack | 110 | 150 | +40 | |
| Defense | 90 | 70 | -20 | |
| Sp. Atk | 154 | 194 | +40 | |
| Sp. Def | 90 | 120 | +30 | |
| Speed | 130 | 140 | +10 | |
| Total | 680 | 780 | +100 |
| Stat | Base | Mega | Relative size | Change |
|---|---|---|---|---|
| HP | 106 | 106 | — | |
| Attack | 110 | 150 | +40 | |
| Defense | 90 | 70 | -20 | |
| Sp. Atk | 154 | 194 | +40 | |
| Sp. Def | 90 | 120 | +30 | |
| Speed | 130 | 140 | +10 | |
| Total | 680 | 780 | +100 |
Mewtwo, number 150 in the National Dex and a Kanto Pokémon, holds Mewtwonite Y to become Mega Mewtwo Y, taking its total from 680 to 780. The biggest single gain is 40 Attack, followed by 40 Sp. Atk. It also loses 20 Defense.
The typing does not change — it is Psychic before and after — so the Mega is the same defensive problem as the base form, only bigger. Mega Evolving replaces Pressure and Unnerve with Insomnia.
As Psychic, 3 of the eighteen attacking types get through for extra damage. It resists 2. The full board is above; the short version is that the types listed under ×2 and ×4 are the ones worth planning around.
Mega Mewtwo Y cannot be used in the current Pokémon Champions regulation, so there is no ladder data for it and no legal set to report. Mewtwo is not legal either, so the whole line sits outside the format rather than just the Mega.
Regulation M-B closes on 9 September 2026, and legality is regenerated from the format data on every build rather than written by hand, so this page will change on its own if that changes.
Smogon publishes no head-to-head checks-and-counters data for doubles formats, so this list is computed, not measured: these are the most-played Regulation M-B Pokémon carrying a damaging move of a type Mega Mewtwo Y takes extra damage from.
Of the 91 Mega forms in the dex, Mega Mewtwo Y is 2nd by base stat total. Its best stat is Sp. Atk at 194, which is 2nd among Megas; its worst is Defense at 70, 85th. One other Mega shares the Psychic typing and therefore this exact matchup board: Mega Alakazam.
A Mega slot is a commitment: the stone occupies the held item, so whatever Mega Mewtwo Y would have wanted from an item, it does not get. Drop it into the team builder to see what the rest of the six then have to cover, or take it to the damage calculator to find out whether those 194 points of Special Attack actually change a knockout.