Sword is possessing a weak human known as Souma. His main goal is to try to regain a new demonic body any way possible. As a human his demonic powers are limited to almost nothing. Later on he obtains helpful items such as bat cat the devil spawn and fragments of Satans soul. He also is currently attempting to overthrow Satan because Satan and most of Hell want Sword dead. For a lowlevel devil Sword is stronger than most demons in Hell. Although in his human form he always ended up in the hospital. Source: Wikipedia