What Mega Evolution changes
Blastoise, number 9 in the National Dex and a Kanto Pokémon,
holds Blastoisinite to become Mega Blastoise,
taking its total from 530 to 630. The biggest single gain is 50 Sp. Atk, followed by 20 Attack. Nothing goes down — HP and Speed stay exactly where they were.
The typing does not change — it is Water before and after — so the Mega is the same defensive problem as the base form, only bigger. Mega Evolving replaces Torrent and Rain Dish with Mega Launcher.
What gets through
As Water, 2 of the eighteen attacking types get through for extra damage. It resists 4. The full board is above; the short version is that the
types listed under ×2 and ×4 are the ones worth planning around.
On the Regulation M-B ladder
Mega Blastoise is played on 8.5% of teams in the Regulation M-B VGC
ladder, which puts it 19th of the 282 Pokémon with enough games to
measure. The move almost every one of them carries is Water Spout at 96.4%.
The Champions module tiers it Uber.
Those figures come from Smogon's published usage statistics rather than from anything measured
here, and they describe what the ladder plays, not what is strongest.
What threatens it
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 Blastoise takes extra damage from.
- Charizard-Mega-Y — Solar Beam (Grass, ×2), on 82.2% of its sets
- Sinistcha — Matcha Gotcha (Grass, ×2), on 97.9% of its sets
- Farigiraf — Thunderbolt (Electric, ×2), on 59.2% of its sets
- Archaludon — Electro Shot (Electric, ×2), on 98.6% of its sets
- Venusaur — Solar Beam (Grass, ×2), on 34.5% of its sets
- Raichu-Mega-Y — Zap Cannon (Electric, ×2), on 98.8% of its sets
Where it sits among the Megas
Of the 91 Mega forms in the dex, Mega Blastoise is 25th by base
stat total. Its best stat is Sp. Atk at 135, which is 33rd
among Megas; its worst is Speed at 78, 62nd.
No other Mega Evolution has the Water typing, so this matchup board is unique to it.
The unevolved Blastoise is itself on 0.15% of teams.
Putting it on a team
A Mega slot is a commitment: the stone occupies the held item, so whatever Mega Blastoise 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
135 points of
Special Attack actually change a
knockout.