It can disrupt opponent combos, remove key characters from the field, and generally hinder their ability to execute their intended strategies
It's somewhat similar to the Giovanni's Scheme 277/XY-P and Here Comes Team Rocket
GXs are a generally more balanced type of card because rather than immediately play some huge basic card like a Charizard EX, you may have to spend a few turns to get out something like a Solgaleo GX or Alolan Ninetales GX
And it will deprive them of the motivation to fight against you
He is notable for the line "Bah, Humbug" which is used to describe Christmas as a fake holiday and to denounce many of the traditions associated with it
For example, in the EX Deoxys expansion, there is a Grumpig card which possesses an attack called "Extra Ball", which deals additional damage if used against a Pokmon-ex