Halcyon Glaze

Oracle Text

Whenever you cast a creature spell, Halcyon Glaze becomes a 4/4 Illusion creature with flying in addition to its other types until end of turn.

Card Rulings

8/1/2008 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.