Elemental Mastery

Text:

Enchant creature
Enchanted creature has ": Create X 1/1 red Elemental creature tokens with haste, where X is this creature's power. Exile them at the beginning of the next end step."

Rulings:

• 5/1/2008 The enchanted creature’s power is checked at the time the ability resolves. If the enchanted creature has left the battlefield by then, its last known information is used.
• 5/1/2008 The tokens will be exiled in the End step even if Elemental Mastery or the enchanted creature has left the battlefield by then.
• 5/1/2008 If the ability is activated after the current turn’s End step has begun, the tokens won’t be exiled until the next turn’s End step.