Grass-type Pokemon are weak against Fire, Flying, Poison, Ice, and Bug-type attacks.
Ice, Fairy and Dragon-typed moves are very effective against Dragon.
Ice, Fairy and Dragon-type moves are super-effective against Dragon-typed Pokémon.
First see what Pokemon they have then remember the Pokemon and the type they are. Get the types that's good against the Pokemon they have and train them to level 100. Water beats Fire Water beats Rock Fire beats Grass Fire beats Ice Fire beats some Bug Grass beats Water Grass beats Rock Ground beats Fire Ground beats some Bug Psychic beats ghost ... ... ...
rock
Grass, Flying and Rock types.
fire type
no Actually yes. There are some Pokemon (dewgong for example) that are water and ice and ice beats water.
Dragon and Ice Types
Grass-type Pokemon are weak against Fire, Flying, Poison, Ice, and Bug-type attacks.
Any fighting, water or grass type Pokemon even ice
Fire beats grass bug steel and ice Grass beats water rock and ground Ground beats electric fire and rock Rock beats flying dragon and steel Water beats rock fire and ground Flying beats grass bug and fighting Bug beats psychic and grass Electric beats flying and water Dark beats dark psychic and ghost Psychic beats fighting Ghost beats psychic Dragon beats dragon Ice beats dragon flying and grass
Ice beats Flying and Grass.
Ice, Fairy and Dragon-typed moves are very effective against Dragon.
You just need to get a good ring on all of them, which will require a good amount of Pokemon purified. For example, Water Type -> Fire Type -> Ice Type -> Grass Type would work since: Water beats Fire, which beats Ice, which beats Grass, which beats Water, and keep going in the cycle. Also, for some reason, you can use Normal Type -> Normal Type -> Normal Type -> Normal Type.
Ice, Fairy and Dragon-type moves are super-effective against Dragon-typed Pokémon.
From my experiences, Rock, Ice, and Dragon. I'm not sure about electricity because altaria is also the dragon type.