Greedy Venom Fusion Dragon

1 "Predaplant" monster + 1 DARK monster whose original Level is 8 or higher Must first be Fusion Summoned. Once per turn: You can target 1 face-up monster on the field; until the end of this turn, change that target's ATK to 0, also that target has its effects negated. If this card is destroyed and sent to the Graveyard: Destroy as many monsters on the field as possible, then you can banish 1 Level 8 or higher DARK monster from your Graveyard and Special Summon this card from the Graveyard.