Nightshade debuted towards the middle portion of Captain Atom's 1965-67 run in Charlton Comics, at first merely an athletically skilled costumed sidekick for the cosmic captain, eventually she would come into her own. Gaining an origin as daughter of an alien princess, granted the ability to transform her body into a living shadow, she would use these abilities selectively so as not to tip off any (including Atom) as to her more than human nature. Her solo series in his back pages was short lived.
In 1968, another commander of the cosmos, Captain Mar-Vell, met a courage and talented young woman named Carol Danvers employed by the U.S. government to uncover the truth about the Kree Captain sent to Earth on a mysterious mission. Instead, she became his partner and, like Atom and Eve Eden aka Nightshade, the two began to express romantic feelings towards one another. It would take nearly a decade until the former security chief gained superhuman powers as Ms. Marvel. At which point, she operated separate of the Captain to stand on her own.
However, perhaps a more direct analogue for Eve Eden over at the House of (rehashed) Ideas was a femme fatale known as Nightshade! In her civilian identity as Tilda Johnson, she was a criminal scientist capable of transforming humans into were-beast that obeyed her command. Undoubtedly the most drastic departure from the Charlton template yet, although she too worked for para-military organizations and encountered her own Captain, America. She wasn't an A-lister.
And so concludes our mini-series for Marvel Mondays. What have we learned, with regards to Marvel's take on Mighty MLJ and Charlton characters? Occasionally, the concept was improved upon, such as the aforementioned Captain Marvel (although he had other influences including the original Captain published by Fawcett Comics). However, the vast majority such as the Human Fly, Scarlet Scarab and Nightshade herself were mere evil copies of the originals. And the heroes cloned after their golden age templates, such as Blue Shield and Comet, ended up a fodder for future death scenes as they never stood well on their own. Hence why we continue to call out to comic fandom and encourage them to look at the classic tales and characters that compose what we here like to call... Charlton vs Mighty MLJ!