If either player Sets a Spell/Trap on your field while this card is in your GY (except during the Damage Step): You can place this card in your Pendulum Zone.
[Pendulum Effect]
You cannot Pendulum Summon, except from the Extra Deck. This effect cannot be negated. Each player applies 1 of these effects based on the number of Set cards in their Spell & Trap Zones.
●0: All monsters they control cannot attack or activate their effects.
●4+: The ATK of all monsters they control become double their original ATK.