Nếu một quái thú Xyz trên sân của tôi bị phá huỷ trong chiến đấu, khi nào tôi có thể kích hoạt hiệu ứng thứ ba của Number 38: Hope Harbinger Dragon Titanic Galaxy ?

LIGHT

2 Level 8 monsters Once per turn, when a Spell Card or effect is activated on the field (Quick Effect): You can negate that effect, and if you do, attach that card to this card as material. When an opponent's monster declares an attack: You can detach 1 material from this card; change the attack target to this card and perform damage calculation. If a face-up Xyz Monster(s) you control is destroyed by battle or card effect: You can target 1 face-up Xyz Monster you control; it gains ATK equal to 1 of those destroyed monster's original ATK.