You can only use the 1st and 2nd effects of this card’s name each once per turn.
(1) While you control a Level 8 or higher Fiend Fusion Monster, you can negate any effect of a monster with currently 0 ATK an/or DEF activated by your opponent.
(2) At the end of a Damage Step, if 2 monsters with 0 ATK battled: You can destroy the opponent’s battling monster.