Interesting, though I can see this being heavily abused in duo
All I need to do is normal PU the doll maker on the field and presto I can multiply target creature twice now. (of course respecting the summoning cooldown)
I suggest increasing the ability cost to prevent it from being abused in such away, especially when it comes to rainbow decks.
Otherwise the singular copy limit does help balance the card and make it interesting in its own way, especially since its defense is low.
Interesting indeed.