The effect that negates the attack is a Trigger Effect.[2]
Neither effect targets.[2]
The Xyz Material is detached as a cost to activate the effect that negates the attack.[2]
During the attack declaration, when the opponent already activated a card like Dimensional Prison, you cannot chain this card's effect.[2]
The effect that destroys itself is a Trigger Effect.[2]
example situation:
Galaxy-Eyes Photon Dragon: If "Galaxy-Eyes Photon Dragon" battles "Number 39: Utopia", then the effect of "Number 39: Utopia" activates when an attack is declared, so you can activate this effect first. If the effect activates, then you can Chain the effect of "Galaxy-Eyes Photon Dragon" to it.[3]
source: http://yugioh.wikia.com/wiki/Card_Rulings%3ANumber_39%3A_Utopia
Neither effect targets.[2]
The Xyz Material is detached as a cost to activate the effect that negates the attack.[2]
During the attack declaration, when the opponent already activated a card like Dimensional Prison, you cannot chain this card's effect.[2]
The effect that destroys itself is a Trigger Effect.[2]
example situation:
Galaxy-Eyes Photon Dragon: If "Galaxy-Eyes Photon Dragon" battles "Number 39: Utopia", then the effect of "Number 39: Utopia" activates when an attack is declared, so you can activate this effect first. If the effect activates, then you can Chain the effect of "Galaxy-Eyes Photon Dragon" to it.[3]
source: http://yugioh.wikia.com/wiki/Card_Rulings%3ANumber_39%3A_Utopia