Gardevoir is a Psychic and Fairy-type Pokémon, which makes it weak against Poison, Steel, and Ghost-type moves. Here are some recommended counters to help defeat Gardevoir:

• Poison-type Pokémon: These are particularly effective against Gardevoir due to its Fairy typing. Examples include Nihilego and Gengar.

• Steel-type Pokémon: These are also effective against Gardevoir due to its Fairy typing. Examples include Metagross and Dialga.

• Ghost-type Pokémon: These are effective against Gardevoir due to its Psychic typing. Examples include Chandelure and Giratina.

Its important to note that Gardevoir can also use moves that could be super effective against its counters, so its recommended to plan ahead and have a strong Pokémon from one of these categories for an awaiting Gardevoir.