Does the mist energy shut off Giratina V shred attack text? " this attacks damage isn't affected by any effects on your opponents active pokemon"?
Yeah if anything the Shred attack text would technically hit through the Mist Energy but I don’t see a situation where that does anything.No, because Shred's text is not an effect. Sort of. It is KIND OF an effect, or more accurately an innate "attribute" of the attack, but it does not place any effect on the Defending Pokemon.