Warning: The following feature contains SPOILERS for Black Lightning, season 3, episode 11, The Book of Markovia: Chapter Two: Lynn's Addiction."
The latest episode of Black Lightning introduced a new method of gaining superpowers into the Arrowverse: gene splicing. While the effects are strictly temporary, the process is reliable and will undoubtedly have major ramifications for Earth-Prime at large.
The central storyline of Black Lightning has centered upon a government agency called the ASA and their efforts over the past four decades to develop an army of metahuman soldiers through genetic experimentation; first under the guise of a publicly-funded vaccine program and then through the controlled release of a street drug called Green Light. For the past two years, the ASA has employed Dr. Lynn Stewart (one of the world's foremost neuroscientists and Black Lighting's ex-wife) to try and stabilize the metagene in the various children they had taken over the years. Most of the ASA's test subjects were put into cryogenic suspension in the 1980s, after they realized that their vaccine successfully triggered the metagene but also caused the newly created metahumans' bodies to burn out quickly. The Green Light formula was slightly more stable, but still left the new metahumans with a host of health problems.
After over a year of study, Dr. Stewart found a protein chain which could be used to strengthen the DNA strands that controlled metahuman abilities. Strangely enough, the chains were unique to the bone marrow of a regular human; crime-boss Tobias Whale, who had been taken into the ASA's custody after he continually interfered in their efforts to take over Freeland while building his own private army of methaumans. While not a scientist, Whale was no fool and he quickly determined that Dr. Stewart was using him as a means of stabilizing the young metahumans. He also figured out that, unlike most of the scientists working for the ASA, Dr. Stewart honestly did care about her charges and was only working for the ASA to save lives, not knowing of their ultimate goal for the children.
Ever the master manipulator, Whale played on Dr. Stewart's good intentions and proposed that they could help each other, pointing out that without him there was no way the ASA could turn the metahuman kids into child super soldiers. After Dr. Stewart provided Whale with a list of all the superpowers they had found among the captive children, he proposed that Dr. Stewart reverse the process that was splicing his protein chain into the kids and use the metahuman gene chain of one of the kids on him. Specifically the chain of one girl who had developed camouflage powers that allowed her to seamlessly blend into any environment and go unnoticed.
After testing the splicing process on Sgt. Grayle (an ASA soldier who had also learned the truth about what the organization was planning and shared her goal of stopping them), Dr. Stewart perfected the camouflage formula. While the splices only lasted for an hour at a time, that was more than enough temporary invisibility for Tobias Whale to escape from the medical wing of the secret ASA base where he was being held. It remains to be seen how Black Lighting will respond to his wife helping his arch-enemy to escape custody or what ramifications temporary superpowers may have on the Arrowverse. However, it seems safe to say that this won't be the last time we see someone acquiring gene-spliced superpowers.