Jason Knoll is the wielder of this weapon. It was created for him and engraved with his DNA, this might explain why his powers led him to it. The sword glows occasionally at certain times, so John wraps it in material to cover the glow so he won't be seen.
Whenever this sword slashes across someone it burns and sears a red glowing scar into the victim, if the victim survives, this scar will be with them for life. The faster this weapon is moved the more heat and fire it generates and can be spun creating a "fire shield" which could protect Jason from explosions and projectiles.