Thousandstar — Piers Anthony

"The CLUSTER series of adventures is set in a future focused on colonization of distant planets, where every living thing has a Kirlian aura that can be measured. Through transfer, a refinement of mattermission technology, the mind and personality of individuals with high aura can be sent to animate a body physically distant. The first three novels in the sequence, CLUSTER, CHAINING THE LADY and KIRLIAN QUEST form a linked trilogy. THOUSANDSTAR, and VISCOUS CIRCLE came later and take place in the time sequence between the second and third volumes of the original trilogy. VISCOUS CIRCLE is a story about a strange and inhuman race of beings and an experimental attempt to transfer into creatures that seem only slightly sapient. They are ultimate pacifists who take the form of magnetic disks that float through space and simply demagnetize and destroy themselves when faced with an unpleasant thought. The bloodthirsty Solarians, in their desperate hurry to find the mysterious Ancient Site, are determined to wipe out the Bands, a strange and beautiful species whose society is an anarchy of peace. Only Rondl, the whirling green Band can save his race, for he has a singular and awesome knowledge. But suddenly Rondl makes a shocking discovery about his identity--a discovery that may cost him his honor, his beautiful lover Cirl, even his very life."