D/D Savant Nikola

You cannot Pendulum Summon monsters, except "D/D" monsters. This effect cannot be negated. Once per turn: You can discard 1 "D/D/D" monster, then target 1 Level 6 or lower "D/D" monster you control; it gains 2000 ATK and DEF until the end of this turn (even if this card leaves the field).

If this card in the Pendulum Zone is destroyed: You can target 1 "D/D/D" monster you control; return it to the hand, and if you do, place up to 2 face-up "D/D" Pendulum Monsters from your Extra Deck in your Pendulum Zones, but they cannot activate their Pendulum Effects this turn. You can only use this effect of "D/D Savant Nikola" once per turn.