You can only use the 2nd effect of this card’s name once per turn.
(1) If your opponent Special Summons a monster(s) of the same type (Fusion, Synchro, Xyz, Link) as a “D/D/D” monster you control: You can inflict 1000 damage to them, also they cannot Special Summon monsters of the same type as those Summoned monsters for the rest of this turn while this card is face-up on the field.
(2) If this card is sent to the GY: You can add 1 “D/D” monster from your GY or face-up Extra Deck to your hand.