By channelingReien through a sword that is reactive to the user's chakra a practitioner of this technique is able to apply the properties of the mystical flames to close combat. Shirokaze Fuyutama, the inventor of this technique, was forced to use a variation of the Spirit Summoning Technique in order to accomplish the production of Reien, while his daughter's ability to produce the flames directly allowed her to bypass this prerequisite.
While this technique doesn't increase the physical cutting power of the user's blade it does allow it to be much more effective against chakra based substances and entities. Enemies slashed by a weapon coated in these flames will be immediately set ablaze , sapping a dreadful amount of chakra from their bodies and disrupting the molding of said energy. For human targets the blaze will quickly wash over their bodies inflicting considerable damage, but countless times less than the same strike on a chakra-based entity. The intensity of the damage this technique can cause at close range is directly connected to the quality of the cut sustained by the victim.