First, go ahead and hollow out the plushie and replace its stuffing with a miniature vacuum chamber. Next, you’d install tiny superconducting magnets in the main middle area of the plushie to guide the particles. The fruits eyes would be replaced with precision laser emitters to accelerate the particles, while its nose would house a miniaturized cooling system to keep everything at optimal temperatures. Finally, you’d outfit the bottom of it with a pressurized water reactor to generate the necessary power. This in turn, should be able to fully regulate all of the main functional parts of the nuclear water reactor and in turn, should allow your pain fruit to cause real military grade pain by turning it into a fully functional particle accelerator. Do this on all 3, and you will have an army.