SuperNova

Supernova is the result of an experiment done by Jossyan in an attempt to put the energy of an entire galaxy inside a weapon. Jossyan knew such thing would most likely not be possible with current technology and limited amount of dark matter, so he made the dark energy constantly teleport along galaxies to where supernovas are happening and grab some of the energy to charge the blade, the blade itself is not sharp, the dark matter inside the blade is surrounded by a layer of specter metal that can let explosive energy through whatever target it hits. Supernova also has an ability to release all its stored energy and target living things through their life energy and blowing them up from the inside.