结界
在你的结束步骤开始时,若你仅操控一个生物,将一个5/5黑色,具飞行异能的恶魔衍生生物放进战场。
If you control zero creatures or more than one creature at the beginning of your end step, the ability won’t trigger. If you control zero creatures or more than one creature when the ability resolves, it will do nothing.