Mega Gyarados swaps Gyarados’s Flying type for Dark type, which completely changes its defensive profile. Goodbye Electric weakness (4× on Flying/Water) — hello immunity to Psychic and resistance to Ghost. The trade is losing the Electric immunity that many teams rely on from Gyarados’s original form. Mold Breaker means Mega Gyarados’s moves ignore the target’s defensive abilities, including IntimidateIntimidateabilityWhen this Pokémon enters the battlefield, the opposing Pokémon's Attack stat drops by one stage.Click to read more →’s Attack-drop (which triggers before damage is calculated).
Its Attack stat reaches 155 base — extremely high. Waterfall and Dark-type coverage moves hit very hard under those conditions.
Mold Breaker and Levitate
One of Mold Breaker’s most important interactions: it bypasses Levitate, which is the ability that makes certain Pokémon immune to Ground moves. Rotom-Wash, Gengar, and Flygon normally float above Earthquake thanks to Levitate. Mega Gyarados’s Earthquake hits all of them.
Type shift consequences
The switch from Flying to Dark means Mega Gyarados loses its Ground immunity (Flying was immune). It now takes neutral Ground damage. Earthquake from opponents is a real threat. Conversely, it gains Dark’s immunity to PranksterPranksterabilityAn ability that gives all Status moves +1 priority — they go before almost everything, even if the Pokémon is slow.Click to read more →-boosted moves — status moves with Prankster (like Banette’s Will-O-WispWill-O-WispmoveBurns the target — halving their physical Attack and dealing 1/16 max HP chip damage every turn.Click to read more → or Thunder WaveThunder WavemoveParalyzes the target — halving their Speed and giving a 25% chance each turn to be unable to move.Click to read more →) don’t affect Dark types.
What stops it
- Fairy-type Pokémon — Fairy hits Dark for 2×. Togekiss, Gardevoir, and Clefable threaten Mega Gyarados hard.
- Fighting-type moves — Fighting hits Dark for 2×. Conkeldurr’s Mach Punch can priority-KO.
- Electric moves — Water is still 2× weak to Electric, and Mega Gyarados lost the old Flying/Electric immunity stacking.