Bulbapedia Generation IV Instead of boosting Fire-type moves' power, Flash Fire now technically boosts the Pokemon's Attack or Special Attack by 50% during damage calculation if a Fire-type move is being used, resulting in effectively the same effect.
Smogon This Pokemon is immune to Fire-type moves. The first time it is hit by a Fire-type move, its attacking stat is multiplied by 1.5 while using a Fire-type attack as long as it remains active and has this Ability.
Serebii Activates when user is hit by a damaging Fire-type move (including Fire-type Hidden Power). Once activated, user’s Fire-type moves deal 1.5 times damage.
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