hmmm the effect is not the problem for me. drawing a card is what´s so strong about it.
if you compare the (non-superpowers) drawing-tricks the 1-ressource cantrips are pretty much the best you can get. for the basic 3-brains/suns "draw two tricks" its kind of a bad thing that there are cards that do half the effect plus an other strong effect on top for half the price. In that regard its almost compareable with teleport although teleport can be played on an empty board but with escape through time you can make sure you win a trade and you can easily play it if you have only one brain left to cycle it. The qualties are compareable but tp´s effect is a bit stronger.
Rustbolt can utilize both. again rustbolt is amongst the strongest zombies at the moment if not THE strongest. this is also part of the reason.
Personally I also think there should be a more control centered card-draw option for both sides... Triplication is ....a start but conjouring is just not as good as drawing your deck.