Pendulum Effect
You cannot Pendulum Summon monsters, except "D/D" monsters. This effect cannot be negated. Before resolving the effect of a Spell Card that would inflict damage to you, you can negate the effect, then destroy this card. This effect can only be used once while this card is in the Pendulum Zone.
Monster Effect
If this card is Normal or Special Summoned: You can send 1 "D/D" or "Dark Contract" card from your Deck to the Graveyard, except "D/D Savant Copernicus". You can only use this effect of "D/D Savant Copernicus" once per turn.