Atoms are consisted of a nucleus and spinning electrons. Most of the atom is empty, but the electrons spin so fast that they are almost a solid sphere. When you stop moving the armor senses that and sends signals that drains all energy as heat, stoping all the movement.
I am totally different armor consisting of biological materials.
If a human or humanoid entered the armor, they would be able to speak through the face mounted microphone. However, I was possessed by a random soul and I speak the same way as Angry Bones and skeleton merchant.