Cupric's beginning in crime happened some time before the events of Ciem 2. Much like Rockpapsci, he based his crimes on a common motif. He was a chemistry student for most of his college career, making him familiar with the effects of copper in a lab. He finally settled on "Cupric" as a nickname, feeling it summed up what he did quite well. His calling card at crime scenes was often a pile of corroded pennies.
Katie Nassita had been devoting her life towards helping Marlquaanites and other misfits to rehabilitate themselves, including serving paroles Eric Copperton and Jordan Reddlewick. Katie ends up being murdered by some of Beliah's men when they try to get her to betray Eric and Jordan's locations. This causes them to violate their paroles and resume their activities as Cupric and Sapphire King. Cupric ultimately sacrifices his freedom to free Extirpon. His partner in the resistance, Sapphire King, reverts to being a criminal and is soon captured during a heist.
Like Rockpapsci, Cupric was forged as a villain in the hopes that he could be a chemistry-themed villain that would serve as a regular in case there were ever demand for a Ciem animated series. So far, he has yet to find much use outside of Abolition. Use of a chemistry-themed villain came from the fact that the Dozerfleet founder liked the sound of "cupric" used in high school chemistry class as a prefix for copper(II) oxide. A chemistry-themed villain had been used before in Replox: Abstract Foundations, named "Molarity."