Cutting assistant in half
Most magic tricks involve comparatively easy explanations, and it is not any different. The trick takes two supporters, maybe not the one which the audience supposes.
One assistant is going to be hidden in the box intended for the other’s legs and will stand them out of the box after it’s time to do so. After the magician separates the 2 halves of their helper after the blade has supposedly cut the person in half, the two assistants can wiggle their arms and legs to allow the audience to know they are fine.