[Set] ■ All «Prism Dragon» monsters on your field cannot be destroyed, returned to hand, or put to other areas, by your opponent's card effects. ■ When your opponent's card attacks, change the target of the attacks to a «Prism Dragon» on your center.
Q2095: What is the target of the attack of my opponent's card when I have "Mirrors Valley" [Set], "Heavenly Crystal Dragon, Aldo Athora" in my center, and "Iron Crystal Dragon, Evaclear" on my right?
A: You can choose either "Heavenly Crystal Dragon, Aldo Athora" or "Iron Crystal Dragon, Evaclear" as the final target.
Since all of the attack target changing abilities belonging to the non-turn Fighter are occurring at the same time, the non-turn Fighter can resolve them in any order. In this case, you can choose which Monster you would like them to target by resolving the effect of the card you want to attack last.