始祖ドラゴン

Text:

威光 ― 始祖ドラゴンが統率領域か戦場にあるかぎり、あなたが他のドラゴン・呪文を唱えるためのコストは少なくなる。
飛行
あなたがコントロールするドラゴンが１体以上攻撃するたび、その数に等しい枚数のカードを引く。その後あなたはあなたの手札からパーマネント・カード１枚を戦場に出してもよい。

Rulings:

• 8/25/2017 You draw one card for each Dragon you controlled that attacked, even if some of them left the battlefield before The Ur-Dragon’s triggered ability resolves.
• 8/25/2017 You may only put one permanent card from your hand onto the battlefield, no matter how many Dragons you attacked with or how many players they attacked.
• 8/25/2017 If a Dragon you control enters the battlefield attacking, it won’t cause The Ur-Dragon’s last ability to trigger.
• 8/25/2017 The Ur-Dragon’s triggered ability resolves after all attackers have been chosen. You can’t attack with some Dragons, put a creature card with haste onto the battlefield, and then attack with that creature. Similarly, any “whenever a creature attacks” abilities of the permanent card you put onto the battlefield won’t trigger.