夺命邪祟

Text:

变身（你可牌面朝下地施放此牌并支付，将其当成2/2生物。可随时支付其变身费用使其翻回正面。）
当夺命邪祟翻回正面时，所有生物得-X/-X直到回合结束。

Rulings:

• 10/4/2004 The trigger occurs when you use the Morph ability to turn the card face up, or when an effect turns it face up. It will not trigger on being revealed or on leaving the battlefield.
• 10/4/2004 The X in the ability has the same value as the X paid in the Morph ability. This is pretty easy to derive since there is no other source of X.