heres a idea how about a power called radiate it radiates the doll making it so that if hes radiated enough he will die and explode and maybe allowing dolls to eat and regen health so like eat apple quarter of health and maybe puke if the doll its too much it pukes out blood or vomit
how about the needle you can put a effect on it for example burning when injected it makes the victim burn to death or freeze they do the power effect
but if u use the needle more then 3 times it becomes infected and if injected again it adds the poison effect to the victim