Two spirits live in every armor and are the soul of the armor. The spirits have a mind, and control the armor. One is good, the other evil. As the Ancient says, the armor follows the will of the one who wears it. What is really happening is the spirit that represents the heart of the bearer controls the armor. The spirits are equally powerful, but the will of the wearer gives power to one spirit so it alone can control the armor. The spirits have a physical form too. They are pale and white as snow. Their hair is the color of the armor as are their eyes. All the good spirits are female and they have hair of the same length (long). All the evil spirits are male and have short, spiky hair. They have no pupils. The spirits are beautiful in human form. If the will of the bearer is manipulated the spirit that is like the will of manipulated bearer will prevail. When the armor is at rest, meaning no one uses it, the spirits become dormant as well.
*note: spirits inspired by Legend of the Kokoro written by Dreamcatcher and Fahrenheit 451 by Ray Bradbury.