It might be interesting to have cards that manipulate the decks in ways that are more complicated than simply drawing from one deck and discarding to the other. e.g. Forward Planning: draw 3 cards then return two of them to the top of your deck. Deja Vu: target moves two cards from the top of their discard pile to the top of their draw deck. Palm Read: draw 3 cards from the target's deck, then return them.
Interesting ideas! I'm afraid this one would be way too powerful. It would be the single most powerful card in the game. Now, instead of one Almighty Hack you would have two coupled with e.g. the Nimble Strike you played just before the hack, guaranteed on your next turn. Deja Vu would be a must have in all decks, you couldn't play competitively without it at all. Play would become pretty much centered around it. Those are bad signs.
I know they're saving deck manipulation for a future class. At least they did when last they mentioned it, which was quite a while ago. So might be a deliberate decision atm.