i dont think its very powerful at all against a mono or duo deck, lets say they have 6 pillars out, which tends to be more than i usually have on the field unless its late in the game, it will do 7 damage per turn for 3 turns, that's 21 damage. a creature with a cost of 4 will probably do around 6 damage per turn (7 if its a phase recluse), but would likely last more than three turns.
*edit- forgot about mark generating quanta, but my point remains that this isnt very powerful against a mono or duo deck with an above average number of pillars/pends out.
also, the cost of 4 would be the basic version, which would also damage you based on your own quanta production. increase the cost to 5 for the upgraded card (only damage the opponent) and you can get even more damage from creatures or permanents at the same relative cost.
and come to think of it, this may be okay for anti-pestal, too.