Also known as a magnetic fusion drive, or a mega-ion drive.
A staple of high end sci-fi is the replicator or the nano-assembler. There is a much more practical and less technomagical way to achieve the same goal. The exciting thing is that this technology exists now, and we're getting much better at it.
Held in a lead sheath the blade of this sword is tipped with uranium and any wound from it, even a tiny one, will go cancerous, although the effects may not show up for months or even years.