There are swords that are on fire, swords made in fire and now, swords that are made of fire. The Backyard Scientist created this “fire sabre” which is basically a seltzer bottle that spits out a stream of butane which lights on fire with a lighter. The look of the fire stream resembles a light sabre, hence the fire sabre.
He also does other fun tricks like light the floor on fire and smacking a water soaked screen in the video below: