This card is similar to mind visions. Getting a spell is probably on average better but you can get useless shit like jade idols. No way a priest has room to fit this card into their broken decks. For one more mana you get to discover a spell from your deck with shadow visions. Also another benefit mind visions has over this is it gives you information about your opponents hand which is much better than information about their deck.
So Mind Vision was bad because it could get you minions? I didn't even see experimentation in Razakus. So I'm sure this won't see any.
I mean, it will see play in my Archbishop Benedictus deck where I try to play your cards. But except that, just won't see any play. This is an early game card. And early game cards are to control those aggro decks. Against those, you are spending 1 mana to get Power of the Wild. The meta has to be very control orientated to see play, and then, Razakus is already great against control to need to play this card.