User blog comment:Linathan/Unit Spotlight: Tundra Scales Zerafalgar/@comment-25160329-20150614160326/@comment-26140304-20150614161922

It gives each ally a 20% chance to inflict Atk Down. If all six units attack, you have a 74% chance of inflicting Atk Down.

Think of this as Tora's BB/SBB/UBB where units have the ability to inflict status ailments upon attacking.