When your opponent activates a Spell/Trap Card, or monster effect, while you have a "Doremichord" card in your Pendulum Zone: Shuffle 1 face-up Pendulum Monster from your Extra Deck into the Main Deck, then apply these effects.
● Pendulum Monsters you control are unaffected by that opponent's effect.
● Cards in your Pendulum Zones cannot be destroyed by that opponent's effect.
● Cards in your Pendulum Zones cannot be banished by that opponent's effect.
You can only activate 1 "Doremichord Formal" per turn.