The episode's greater meta plot, as revealed here, uses several concepts from Supergirl (2015). Normal humans becoming possessed by Kryptonian souls, gaining all their superpowers, was used in Season 3 of the parent show. Amusing enough, that season also had Morgan Edge as the Big Bad of the first half. Earth building Kryptonite weapons to use against an evil Superman was explored throughout the original show, but dealing with an imminent invasion was the crux of the Season 2 finale, albeit the enemies were the Kryptonian-adjacent Daxamites then. The Big Bad being a relative of the title character was also used in the parent show's Season 1.
Jordan's first experience with kryptonite.