Holy Fire Reiki was introduced by Reiki Master William Rand and the ICRT in 2014. Although I was Certified as a Holy Fire Karuna Reiki® Master, I do not offer classes in this System of Reiki.
In 2014, I read an article about Holy Fire Reiki in the Reiki News Magazine and had been asked by several students about it. In August of 2014, I took the class and received my Registered Holy Fire Karuna Reiki® Master Certification. For about 3 months after my attunement, I worked with the energy, but did not sense a difference in the energy that I was channeling. As it was required that I teach only Holy Fire Reiki after being attuned to it, I withdrew my name from the Registered Teacher list as I did not feel it was my path. I continued teaching the Usui/Tibetan Reiki Ryoho and Karuna Reiki® which is what we currently offer at our Training Center.
Since that time, I have heard of other Reiki Masters having the same experience with Holy Fire not resonating with them.
Everyone has their own experiences, so I would recommend you use your own guidance and intuition.