結界
每當任一對手施放每回合中其第二個咒語時,你派出一個珍寶衍生物。
The ability can trigger once each turn for each opponent.
It doesn't matter if Monologue Tax was on the battlefield for the first spell. It also doesn't matter if that first spell resolved or not.
Nothing special happens on the third spell, fourth spell, and so on.