Text: ATTACK Once per Round, when I'm defended [1]: Rest 1 of your Rival's Crystals.
FAQs/Rulings
Can multiples of the same card use a "Once per Round" effect?
No. “Once per Round” effects can only be used once each Round across all cards that share a name and tag.
Is this effect mandatory?
No, Crystal costs are optional and must only be paid if you wish to use the effect.
If my Rival defends against this Ally's attack and I use a card effect to remove that defender from the Combat Area, can this Ally's effect still be used?