Opal Guardian
Enchantment
When an opponent casts a creature spell, if Opal Guardian is an enchantment, Opal Guardian becomes a 3/4 Gargoyle creature with flying and protection from red.
It was a moment in time, cast in stone—a moment whose time had come again.
イラスト：
Time Spiral#30レア英語適正
裁定
2006年9月25日
Guardian’s effect doesn’t wear off.
2006年9月25日
After the triggered ability resolves, Opal Guardian is no longer an enchantment.
2006年9月25日
A face-down creature spell will cause Opal Guardian’s ability to trigger (if it’s an enchantment).
2008年8月1日
A noncreature permanent that turns into a creature can attack, and its 
abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature.