The Flash's latest villain, Weather Witch, ends up rewriting the Arrowverse's rules that have been in place since The Flash season 1. The character, who's related to The Flash's Weather Wizard, also marks an interesting change to a legacy from the classic comic books.
The Flash season 5 episode 7, "O Come, All Ye Thankful," saw strange weather phenomena springing up around Central City, indicating that Mark Mardon (aka the Weather Wizard) was on the loose. As Barry Allen was in the middle of making sure the weather-manipulating metahuman was still securely locked up in Iron Heights Penitentiary, the prison was attacked by a young woman armed with a weather-vane that she wielded like a staff. She was identified as Jocelyn "Joss" Jackam - Mark Mardon's estranged daughter, who had it out for her father and was determined to kill him for abandoning her as a child. It was later determined that Joss' "staff" was a newly discovered piece of meta-tech, which gave its holder weather-control powers identical to those of the Weather Wizard.
The Weather Witch's path to power is notable in that it closely mirrors her father's origins in the comic books, rather than his background on The Flash. In the original comics, Mark Mardon was a thief who stole a weather control device (The Weather Wand) from his scientist brother. In the television series, Mark Mardon was one of many people who developed superpowers as a result of the STAR Labs particle accelerator explosion. This accident helped to create a common unifying event during the The Flash season 1, so the writers didn't have to explain a different supervillain origin story every week. This resulted in many villains from the comics, like Weather Wizard, being reimagined as metahumans rather than career criminals armed with advanced technology.
Another interesting aspect of Weather Witch's character is how she changes another aspect of her father's legacy. In the original Flash comics, Mark Mardon was a father, but he had a son rather than a daughter. Joshua Jackam was the result of a one-night-stand between Mardon and a woman named Julie Jackam. There was no indication as to who Joshua's father was until the baby began manifesting metahuman weather control powers. This prompted Mardon, whose powers came from his Weather Wand, to try and kidnap the child with the intention of finding a way to take young Joshua's powers for himself.
So why change the son of the Weather Wizard into a daughter for The Flash TV show? Presumably so the character would better fit the episode's theme of fathers and daughters failing to get along. The Flash season 5 episode 7 had another subplot involving Nora West-Allen arguing with her father, Barry Allen, over his risking his life in ways she felt were unnecessary. The episode also featured a series of flashbacks detailing Cicada's origin story, and how he was inspired to become a serial killer who targeted metahumans because of his adopted daughter being rendered comatose as a result of a metahuman street fight. Changing Joshua Jackham to Joss Jackam better fit the narrative of the episode and allowed the introduction of a new piece of meta-tech.
There is some irony that The Flash flipped the script in this instance, creating a legacy villain who used technology to mimic her metahuman father when the original character was a tech-based villain whose son became a metahuman. It's a credit to the show's writing team that they could think of such a drastic change and work it into the on-going narrative so smoothly. Plus, it means that future villains may go back to what The Flash comics presented in the first place: villains who use technology rather than superpowers. Such creativity suggests audiences can look forward to big things in The Flash's 100th episode as well as the upcoming Elseworlds crossover event.