The Fire Element is the Sword Arm of Darkness. It was claimed by Darkness during The First Heavenly War, and was used against Uranus and turned the tides of the war. It is the base element for the bodies of the humans that reside on a planet called Earth.
Its polar opposite is Wind, though of course wind is needed for its exsistence. Fire consumes and spreads if not taken care of, and is the element of heat. It is also one of the elements comprised of a star, so of course one of the element of star pieces.