When you declare an attack with this card against a monster of the selected Type, and the opponent activates “Mirror Wall”, the ATK will be halved first at attack declaration, and then increased by 1000 during damage calculation. So the final ATK will be 1500 = (1000/2) + 1000. Similarly, if the opponent activates the effect of “Fairy Box”, the ATK of this card will become 1000, because the 1000 point increase occurs after its ATK is reduced to 0.