edit - dunno. normally this spell was super poweful in druid with their ramp spells and powerful draw tools. I am really skeptical this will work in mage (unless ele mage includes the legendary weapon).
This is a very powerful effect, druid has shown that with pre-nerf Innervate since it generally was used to get out minions earlier. However, 1) Is this card strong enough to risk running in a Book of Specters deck, and 2) if not, is there some other elemental mage build that is good enough with this card that you're willing to drop the books?