Mold Breaker ignores the following Abilities, even in situations where the target's Ability could increase the power of a move if it weren't ignored (such as using Low Kick on a Pokémon with Heavy Metal or using a Fire-type move on a Pokémon with Dry Skin).
Dry Skin makes user weak to Fire-type moves just like Fluffy. Bulbapedia mentions that Fluffy is ignored by Mold Breaker so this means it will have normal power.
Hope this helps.
