Sabrina

Sabrina is undoubtedly the best Supporter card. Playing this will switch out your Opponent’s active Pokémon with one of their choosing from their bench. This is a great way to force them to bench a tough ex card or to bring out a weak Pokémon you know you can beat in one turn.
Some might argue that Pidgeot can be a more consistent way to use such an effect, but Sabrina requires no setup in return. Unless your opponent has a stacked bench, using this is a great way to disrupt their strategy.