Prettied up the Main post.
Added the Details to the Additional Notes.
Suggestions
Give the Doll the skill "Voodoo X" where X is the Targets side and Creature slot.
Ie. the opponents first creature would be "Voodoo o1"
Ie. the opponents seventeenth creature would be "Voodoo o17"
Ie. your allied first creature would be "Voodoo a1"
Ie. your allied Twenty-first creature would be "Voodoo a21"
Have voodoo redirect any action to the affected target instead. This would prevent parallel Conundrums where you have to do multiple things that conflict. Like Fractal filling your hand with dolls and the voodoo'd creature at the same time. Reverse time creating a doll that does nothing or a doll that has to link again.
Also that if the target leaves play the Voodoo doll simply loses its Voodoo ability or better could gain the targets ability and attack as a bonus.
People like the idea so I'm thinking of way to make it plausibly codeable in the game. An idea that can never possibly work is useless.
I like the first suggestion about Voodoo X creatures, could make it a lot easier to implement, and the third one with the doll gaining the target's attack and HP as a bonus. (Adding these to main post)
However, for the second point I like to have
both the doll and creature take the same punishment/bonus instead of just the original creature, which would take out the voodoo theme of the card.
@ SG
I know that the cost for the upgraded version is a large difference, but then so is dusk mantle (I used those costs)