Select 1 face-up card in the Spell & Trap Card Zones and destroy it. The controller of the destroyed card can then Set 1 Spell or Trap Card from their hand. If this Set card is destroyed and sent to the Graveyard, select and destroy 1 face-up card on the field.
Mirror Wall can be activated in the Damage Step since it alters a monster's Attack, but Wild Tornado cannot be activated in the Damage Step, so it cannot be chained to Mirror Wall (if its activated in the Damage Step)
Is there a bug with this card where it can't destroy special summoned monsters such as fusion or ritual? Used it in a nephthys deck but it failed big time... Am I getting something wrong about this mechanics?