The quick answer

Minior takes 1.6× damage from Electric, Ice, Rock, Steel and Water attacks in Pokémon GO. Its type does not change when the core is exposed.

The combined Pokémon GO type chart

Damage takenAttack types
1.6× · weakElectric, Ice, Rock, Steel, Water
1× · neutralDark, Dragon, Fairy, Fighting, Ghost, Grass, Psychic
0.625× · resistedBug, Fire, Flying, Ground, Normal, Poison

Why Ground is resisted, not super effective

Looking only at Rock makes Ground seem like a good answer. But Minior is also Flying. Pokémon GO treats the main-series Ground immunity as a strong resistance, which combines with Rock’s weakness to produce a net resistance.

The result is 0.625× damage in GO. Do not copy the literal zero-damage Ground immunity from a main-series type chart, and do not ignore Flying and call Ground a weakness. Both shortcuts give the wrong answer for this game.

Fighting and Grass cancel to neutral

Fighting is strong against Rock and resisted by Flying. Grass follows the same pattern. The opposing multipliers cancel, so both attack types deal neutral damage to Minior in Pokémon GO.

That does not mean every Fighting or Grass Pokémon loses the matchup. A Pokémon may carry a coverage attack, enter with stored energy, or benefit from a shield advantage. This table describes incoming attack types rather than predicting an entire battle.

Typing stays fixed while bulk changes

The shell and the exposed core share Rock/Flying. Their defensive matchups therefore remain the same. What changes is the stat profile: the exposed core has less Defense, so the same unresisted hit can become harder to survive.

In PvP, pair a theoretical type advantage with timing. If you expect the next hit to expose the core, consider the follow-up attack as well. A narrow win against the shell may not tell you what happens after the transition.

Choose counters for a real encounter

Start with a suitably powered Water, Electric, Ice, Rock or Steel attack, then check the user’s secondary typing and Minior’s move coverage. Do not assume a Pokémon’s own type tells you the type of its actual attacks.

This is a weakness reference, not an announcement that Minior is a current raid boss. The verified debut encounter method is wild spawns. For raids, always check the live boss rotation and a simulator for that particular encounter before assembling a team.