I've messed around with voodoo decks that some people here suggested, and it gives me an impression that a deck just based on voodoos for damage is far from enough to kill off the opponent. I think it is mainly because of the fact that it must be effective as a combo, which is sometimes quite slow even for AI3.
I think the best use of this card is to put them in rainbow decks and act as a dummy for AI's CC?
this card provides a lot of probability but is well balance
unstable gas is much more effective for dealing that 20 damage
tradition speed poison is much more faster than poisoning the doll
other rush decks are much faster than the rage potion doll combo
these damaging dolls combo are slow, and cannot provide good defense (most card slot are used for combo)
so I think the gravity pull doll is the most potential one...
but not for PvP (only AI will madly try to kill your dolls and play as many creatures as they can)