The Marvel Comics storyline House of M culminated in the most horrific and sudden threat mutants had ever faced during an event known as M-Day, when Scarlet Witch eliminated most of the mutant population with a single phrase, and all of that could have been prevented by one MCU hero. With the inclusion of Netflix’s Daredevil and Kingpin in recent outings of the Marvel Cinematic Universe, it is safe to assume that the other Netflix/Marvel heroes are also now members of the MCU. And in the possible outcome glimpsed in a Marvel What If?... story, fans learned that one live-action hero could have prevented Wanda Maximoff's darkest moment.
In What If Jessica Jones Had Joined the Avengers? by Brian Michael Bendis and Michael Gaydos, fans learn what would have happened to Jessica Jones if - after breaking free of the Purple Man's control - she had accepted the Avengers' invitation to join them. After proving her astounding mental and physical strength, the Avengers ask her to be a part of the team and while she still turns them down, she does agree to be their SHIELD liaison - a move which, given her powers, effectively makes her one of the team. The timeline shifts on Captain America's decision to go back and talk to Jessica a second time, sending a huge ripple effect on the events that follow.
Once Jessica Jones is working alongside the Avengers, she begins to familiarize herself with the team and their facility. While making herself comfortable, Jessica also uses her natural investigative talents to make sure everything within the Avengers tower is on the up and up, including the Avengers themselves. When Jessica Jones comes across Scarlet Witch, she notices that something is off about her and realizes Wanda is on the verge of a mental break. When Jessica brings this to the attention of Captain America, Steve alerts both Doctor Strange and Charles Xavier, who quickly give Wanda the help she needs. Jessica Jones notices Scarlet Witch’s mental distress when no other Avenger does, preventing Wanda ever altering reality to bring about the House of M.
Jessica Jones in this What If…? issue shares some key similarities with the version depicted in the MCU while also setting up a potential future for the character moving forward in the live action realm. Jessica’s storyline with Killgrave in this comic is just as it was depicted in the comic series Alias, which was the main inspiration behind the Netflix original series. Sadly, in the mainstream timeline, Jessica was too traumatized to accept the team's offer, but had she done so, one of Marvel's most epic events would never have come to pass. In many ways, the story is an indictment of the Avengers, who missed all the signs of Scarlet Witch's condition which were so apparent to an outsider.
Jessica’s investigative skills would have saved countless mutants while also genuinely helping a fellow teammate who has been left fighting for redemption ever since. Sadly, this wasn't to be, all because one conversation went slightly differently. Using the skills that make her more than just a superhuman, but an actual hero, Marvel Comics confirmed that one MCU hero, Jessica Jones, could have prevented Scarlet Witch's House of M if she had only joined the Avengers in the main continuity.