For Haunter's "Gothic Fear" Ability, can I choose to confuse only one of the Active Pokemon or must BOTH of them be Confused?
It's either both or none; you cannot choose only yours or only your opponent's Active Pokemon to be Confused.
Gothic Fear



x2
-20Gothic Fear
When you play this Pokémon from your hand to evolve 1 of your Pokémon, you may leave both Active Pokémon Confused.

Poison RingYour opponent's Active Pokémon is now Poisoned. That Pokémon can't retreat during your opponent's next turn.
For Haunter's "Gothic Fear" Ability, can I choose to confuse only one of the Active Pokemon or must BOTH of them be Confused?
It's either both or none; you cannot choose only yours or only your opponent's Active Pokemon to be Confused.