Lu K’uan Yu “Taoist Yoga: Alchemy and Immortality”.
This one was emphasized to me by a woman I once healed using the Reiki energy while she was in a trance after re-experiencing old trauma memories during the healing.
It’s a bit technical, but goes deep into the methods used to cleanse and transform the generative force and what the long term benefits can be.
I know, not the most thrilling or titillating use of that power, but definitely worth it for those of us who are choosing to walk a certain path.