When a monster effect activated by your opponent resolves, if that opponent's monster has 0 ATK or DEF, and you control a Level 8 or higher Fiend Fusion Monster, you can negate that activated effect. At the end of the Damage Step, if monsters with 0 ATK battled each other: You can destroy your opponent's battling monster. You can only use each effect of "Branded Disciple" once per turn.