by bluewizard
Hello,Here is where things are a little different than Magic and WoW. You can only cast a spell in your turn (Unless the card says otherwise).
So for reverse magic to work it must already be face down on the target of the incantation or enchantment spell. In this case the opponents panther creature.
The other thing of note is the enchantments with the red circle on their reveal costs MUST be revealed when the reveal conditions are meet. Like here if a creature has the reverse magic face down on it and the first spell is something not all that great you still must reveal it to redirect the spell to the caster.
I hope that helps.
Thanks
-Ryan