The Graviton Spear is ex-Toa Hagah Barionk's Toa Tool, which can be used to focus his Elemental Power of Gravity. It can also function as a melee weapon. The spear itself has the ability to create small, but powerful back holes, which can draw energy and objects into itself. However, the use of the spear weakens Barionk, so he has to be careful how much he uses it.