Kuwabara's Rei-ken is a combination between this and a Laser Blade, since it's made of his own ki. Hiei in YuYu Hakusho occasionally uses the Sword of the Darkness Flame.One spark from a clash of swords, and all the fats and oils the sword's soaked up go into a blaze. Instead of using magic or a napalm-like substance, Shishio's sword burns because, after using it to kill countless people, the blade's serrations have become filled with human fat. In Tsubasa -RESERVoir CHRoNiCLE-, through a unique mishap involving a virtual MMORPG and a Reality Warper feather both Syaoran and Kurogane end up with flaming swords outside of the game as well.
Later on, his sword gets bigger the more he uses its power, and gradually it gets to the point where it's completely enveloped in flames.
