This effect is constantly applied during the Damage Step. If “Skyscraper” is on the field and this card battles an “Elemental Hero” Fusion Monster, that Fusion Monster’s ATK will still be 0 for Damage Calculation.
If this card battles a Fusion Monster that is equipped with “Axe of Despair”, etc. that Fusion Monster’s ATK will be 0 for Damage Calculation.
If “Shrink” is activated in the Damage Step targeting a Fusion Monster battling “Fusion Devourer”, that Fusion Monster’s ATK will be 0 for Damage Calculation.
This is a Continuous Effect.