Weakness doesn't apply to benched pokémon

TaurusFire

Weakness currently doesn't apply to benched pokémon. For example Blizzard from Articuno ex does 10 damage to all benched pokémon as well, it would be nice if weakness actually worked on that as well

Jadite

https://community.pokemon.com/en-us/discussion/13633/weakness-doesnt-apply-to-benched-pokemon

Weakness has never applied to benched pokemon because weakness or resistance is only for damage from attacks, not effects of attacks.

DoubleCure

https://community.pokemon.com/en-us/discussion/comment/54192#Comment_54192

The reason weakness it's not applied by default to the bench Pokemon it's not just because of effects of attacks (like damage counters)…

In fact the Articuno ex Blizzard attack does damage from the attack to the bench Pokemon (that's why in this case Manaphy would protect the bench), but anyway… weakness it's not applied by default to bench Pokemon because it's a game rule, the only way weakness could be applied to bench Pokemon it's if the card explicitly says it.