If your opponent has "Necro Gardna", "Shield Warrior" or "Friller Rabca" in the Graveyard, this card will prevent their effects from activating as long as he continues to attack.
This card's effect suppresses the effects of recruiter monsters like "XX-Saber Emmersblade", if it destroys them by battle.
Since this card can only negate effects when it attacks, you can still use cards like "Mischief of the Yokai" during your opponent's Main Phase.