This is literally the most broken card in the entire game. And I mean design-fail level flawed one. It just must be auto-include in any deck able to cast it (having hero with a lore resource icon, or Song of Wisdom). The card costs nothing. It replaces itself, filters a player deck and you can even play it when you draw it and quest prevents you from getting any resources (I mean no rebuy, just zero cost). Imagine you have two combo piecies in your deck and no limit for a number of copies in a deck. Would you be better running 25 card A and 25 card be? Or one copy of card A, one copy of card B, and 48 copies of this madness? You could draw 15 cards A in a row and never assemble the combo. Similarly, you must have noticed how Surge keyword is anoying. Imagine simple treachery card: "The first player chooses a character. Deal 1 damage to that character. Surge." Well, encounter deck consisting only of copies of such card would make you lose on the spot! In Magic the Gathering, this would be the best card printed ever, like 500% than Black Lotus. I don't get how this could ever see print.