I will not use the same effect as the old voodoll to redirect damage : you won't need to link the voodoll to a target. It will redirect damage to specific cells near the voodoll and increase the damage done. Currently, I think about the 4 four cells which are in line at 3 cells away from the Voodoll.
Double uses there : 1) it increases damage done 2) it allows melee to deals without being in melee 3) with optimal placement, it is possible to affect several target at the same time.
Btw, Kikuihimonji, the solution is not as simple as « you can make ally friendly spells have different effect when cast on "ally voodoll". » unfortunately. This means having to modify all the spell from all class for a specific operation on a class. It's not even an option.
I will obviously search for a clean solution but the only one that might work (not sure, not tested yet) can generate many other bugs.