Epsilon Energy (or, Epsilon Radiation) is a stable Ionized Particle capable to generate energy to power machinery as well as propulsion. It can also be weaponized to generate a focus Particle Wave. It is also a catalyst for many other energy, especially Thalaron radiation and the Omega Molecule.
During the Events of War of the Universes and Project Lancer, The Terran Empire use this energy to power their most powerful weapons including Project L.A.N.C.E.R.. In Lost in the Multiverse, Universe 116-A relied on Epsilon Energy in all their technologies. It was also weaponized making the extremely powerful Particle Cannon.