This will, presumably, have 7 mana-sources of yours tapped down, meaning it will bleed no less than 7 points every turn cycle. More likely, this holds your opponent back for a turn (blocking 7+ lands and a pack of creatures you wanted to hold off, 13+ permanents doesn't seem unreasonable), holds you back for a turn, and then breaks on your opponent's second turn. If I'm reading right, it will still block all untapping even if it only has 1 counter left, so what you've basically done is cast a 7 mana "Time walk, but your opponent draws 2"... at least until turn-by0turn value drips come into play, like Planeswalkers. Seems good if you can math it to get that result.