Robot Adept by Piers Anthony

These excerpts reveal a complex narrative involving two parallel worlds, Phaze (ruled by magic and Adepts) and Proton (governed by science and Citizens), and four central characters caught in a crisis of forbidden love and inter-dimensional identity exchange. Mach, a self-willed robot from Proton, and Fleta, a shapeshifting unicorn from Phaze, seek refuge from opposing factions—the Adverse Adepts and the Contrary Citizens—who view their union with disdain. Simultaneously, their counterparts, Bane (Mach's human mind in Phaze) and Agape (an amoeba-like alien from Proton), are struggling to navigate their exchanged lives while being manipulated by the hostile groups; Bane is spying on the Adepts in Phaze, and Agape (mistaken for Fleta) is forced to compete in a Proton Tourney as a means of protection. The text details their attempts to survive, perform magic, master alien bodies and customs, and ultimately reunite to reverse the confusing body-swap.