you should use water types because they are strong against fire types
Flying and or fire types
just beat the elite four and catch 60 different types of pokemon. prof oak will giv u the national dex and a tripass
You make all their Pokemon faint and you should vary the Pokemon to their weakness types
The types of pokemon the Elite Four use in Pokemon Y are: Steel, Fire, Dragon, and Water. The Champion uses a variety of types.
You should use mostly grass and flying types they would be most effective
No. You should figure out what Pokemon types they have and build your team around that.
Ground types and psychic types beat poison types.
There are 3 sticker types you can collect: One for defeating the elite four, Two for hatching Pokemon eggs, Three for defeating your friends in link battles.
You have to beat the elite 4 and catch 70 types of Pokemon then go to professor oak and he will give the national dex then talk to cilleo on first island
types 2 use: grass, water, fire, electric, psychic, dragon.
Your starter Pokemon, and 5 other Pokemon of differing types that are of a decent level (40) and check other websites to make sure you can battle all types with your team.
There is no "best" Pokemon because every Pokemon has its own weaknesses and strengths against other types of Pokemon,