I don't think this ruling was looked at all the way.
Electivire Lv.X says to
"Discard all of your opponent's Pokemon Tool Cards..."
Mismagius says to
"Choose up to 4 in any combination of Pokemon Tool cards and Technical Machine cards in play (both yours and your opponent's) and discard them..."
Neither of them say anything about doing something to any of the opponent's Pokemon. Unown G only prevents effects of attacks done to the Pokemon that it's attached to. The effect is done to the play area or the opponent's play area.
It's the same as how Gardevoir's Psychic Lock is done to the opponent's play area. The opponent doesn't have any Poke-Powers that it can use, the opponent's POKEMON have Poke-Powers that the opponent can no longer use.
Nothing is happening to the opponent's Pokemon with Electivire Lv.X or Mismagius any more than is happening when Gardevoir attacks.
The effect of the attacks are done to the Pokemon Tool cards, not to the Pokemon that they are attached to.
