The blade of this sword is essentially a crystallized spike of raw Kryptonite, which has given it such an unimaginative name. Kryptonite, despite its name, has no relation to the element Krypton. Kryptonite is instead an extremely rare mineral which is chiefly composed of Monosodium Glutamate (which gives it a delicious earthy taste) and Copper Carbonate (responsible for its startling green colour). The Kryptonite sword, however, has been worked upon by a master of the dark arts, which has given it a great cutting edge and a magical poison which is transferred to the victim upon a sharp stab of the blade. The poison is responsible for its sickly glow. Swords like these are thought to be responsible for the death of an ancient race of super-heroes; a superhuman bunch similar to normal modern day Heroes and who are thought to have been highly allergic to Kryptonite. Nobody knows much about it.