Also called and considered Hyper Matter, it is a form of exotic matter, used for generating energy
Subspace Matter is matter scooped from subspace. There are an near infinite variety, but the one in question has properties akin to Tetryon and Tachyon particles. Because of this, it is highly unstable as it desires to move at FTL Speeds, and has to be held in Fusion devices
It also requires reactant fuel, to be used.
- Based on Hypermatter from Star Wars.