Can you respond with Reactions to ETB (enters-the-battlefield) triggers?
Ruling: Yes, you can respond with Reactions to ETB triggers. While you cannot respond to units being played, you can respond to their ETB triggers when they go on the stack.
Ruling: Yes, you can respond with Reactions to ETB triggers. While you cannot respond to units being played, you can respond to their ETB triggers when they go on the stack.