What Mega Evolution changes
Gengar, number 94 in the National Dex and a Kanto Pokémon,
holds Gengarite to become Mega Gengar,
taking its total from 500 to 600. The biggest single gain is 40 Sp. Atk, followed by 20 Defense. Nothing goes down — HP and Attack stay exactly where they were.
The typing does not change — it is Ghost and Poison before and after — so the Mega is the same defensive problem as the base form, only bigger. Mega Evolving replaces Cursed Body with Shadow Tag.
What gets through
As Ghost and Poison, 4 of the eighteen attacking types get through for extra damage. It resists 4 and is outright immune to 2. 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 Gengar is played on 4.9% of teams in the Regulation M-B VGC
ladder, which puts it 30th of the 282 Pokémon with enough games to
measure. The move almost every one of them carries is Protect at 99.4%.
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 Gengar takes extra damage from.
- Kingambit — Sucker Punch (Dark, ×2), on 99.8% of its sets
- Incineroar — Throat Chop (Dark, ×2), on 44.4% of its sets
- Garchomp — Earthquake (Ground, ×2), on 85.7% of its sets
- Basculegion — Last Respects (Ghost, ×2), on 99.9% of its sets
- Farigiraf — Psychic (Psychic, ×2), on 54.4% of its sets
- Gholdengo — Shadow Ball (Ghost, ×2), on 99.1% of its sets
Where it sits among the Megas
Of the 91 Mega forms in the dex, Mega Gengar is 49th by base
stat total. Its best stat is Sp. Atk at 170, which is 7th
among Megas; its worst is HP at 60, 82nd.
No other Mega Evolution has the Ghost and Poison typing, so this matchup board is unique to it.
The unevolved Gengar 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 Gengar 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
170 points of
Special Attack actually change a
knockout.