Electro will change the MCU in major ways when the character appears in Spider-Man: No Way Home. With Jamie Foxx reprising his role from The Amazing Spider-Man 2, the door is wide open to the multiverse. It's also open to a major supervillain team comic book readers have longed to see on screen: the Sinister Six.
The Sinister Six are the combined forces of Spider-Man's most dangerous foes, and they've been making his life very complicated from their first appearance in 1964. The team has evolved, growing more dangerous in every incarnation, with some of the most unique and sinister coming from the multiverse of the comic books.
Formed By Doctor Octopus
Comic book fans of Doctor Octopus are likely to know that he formed the team in The Amazing Spider-Man Annual #1 in 1964. Obsessed with revenge for his many defeats at the hands of Spider-Man, he puts a call out to all of Spider-Man's villains.
Only five others answer, including Electro, Mysterio, Sandman, the Vulture, and Kraven The Hunter, a Spider-Man villain soon to the focus of his own movie. The team can't make up their minds on who will get the honors to take down the Wall-Crawler, which sets the stage for their first rumble with Spider-Man.
Individual Defeat
The Sinister Six kidnaps Betty Brant and Aunt May in an attempt to lure Spider-Man out. The problem with their plan is their individual greed to be the one to defeat Spider-Man leads to them deciding to make him run a gauntlet through them one by one.
Though the first version of the team is composed of some of the most powerful members of the Sinister Six, he manages to take them all down. Their inability to work together cements their eventual defeat, a theme that would play out in the future.
Return Of The Sinister Six
Despite the significance of the Sinister Six, there was a fairly long period in the comics between their first and second iterations.
The second version of the team forms in "Return Of The Sinister Six" in The Amazing Spider-Man #334–339 in the late 80s. This team is mostly the same lineup as the first, with the exception of the Hobgoblin. He replaced Kraven The Hunter, who had recently died in the pages of Kraven's Last Hunt, one of the coolest storylines from the comics that his upcoming movie could possibly adapt.
Becoming The Sinister Seven
From there, the Sinister Six would become a more consistent presence in the life of Spider-Man. Their next major iteration would be the Sinister Seven. This team forms during The Clone Saga, banding together when Kaine, the evil clone of Peter Parker, starts hunting down and killing Spider-Man villains.
Though The Clone Saga is unlikely to be a comics crossover the MCU adapts anytime soon, the concept of the Sinister Six coming together in the MCU because someone is hunting them down might be an option if the characters don't cross paths with the MCU Spider-Man.
Sinister Twelve
Things would only get worse and worse for Spider-Man as time went on. The Sinister Seven would become the Sinister Twelve in the early 2000s. Marvel Knights Spider-Man sought to bring a more mature take on the hero in its run beginning in 2004. Part of that was a much more powerful and dangerous Sinister Six.
The team doubled its roster, organized by the Green Goblin, Norman Osborn. The roster included Scorpion, the Vulture, the Sandman, Electro, the Chameleon, the Lizard, Hydro-Man, the Shocker, Hammerhead, Boomerang, and Tombstone.
Ends Of The Earth
In 2012, Marvel Comics celebrated the 50th anniversary of Spider-Man with the "Ends Of The Earth" storyline. The Sinister Six reforms, led by Doctor Octopus and with the Rhino and the Chameleon now members.
The story hinges on an elaborate plot by Doctor Octopus to hold the world hostage to a deadly space weapon. Spider-Man and the Avengers confront the team, but it's one of the most brutal fights between Peter Parker and his longtime enemies. The Sinister Six take control of the minds of the Avengers and use them against Spider-Man.
Superior Six
Not too long after his defeat in "Ends Of The Earth," a dying Doctor Octopus finally gets his revenge against Spider-Man. He swaps his consciousness with Peter Parker's, taking control of his body.
Octavius masquerades as the Superior Spider-Man, and reforms the Sinister Six, this time as the Superior Six. Octavius uses mind control to use the villains as his partners, leading them into a battle with the Wrecking Crew. During the fight, they break free of their mental bonds and turn against him, not realizing he is actually Doc Ock in Spider-Man's body.
Renew Your Vows
Many alternate versions of the team exist throughout the main Marvel continuity, but there are many other versions in the multiverse as well. One of the most interesting and dangerous is the Sinister Six from the Renew Your Vows reality. This 2015 storyline imagined a future where the team is employed by the Regent to hunt down Spider-Man.
Doctor Octopus, Kraven the Hunter, Hobgoblin, Mysterio, Shocker, and Vulture hunt down Spider-Man, who has been in hiding for a long time. He's also married again to Mary Jane and they have a daughter, Annie, who becomes Spider-Girl.
Infinite Variations
The Spider-Verse has become a major component of Spider-Man lore in the comics, and is about to become a major component in the MCU. With that being the case, it's likely some members of the Sinister Six will come from different realities in the movies.
Many exist in the comics, such as the steampunk version of the team from Earth-803. This team was introduced in the Spider-Gwen comics. There is also a version from the Marvel Zombies universe, as well as one from the Age Of Apocalypse storyline, though this team was created by the evil X-Men villain Mr. Sinister.
The Ultimate Six
One of the most significant alternate reality versions of the Sinister Six, and one that may have the most bearing on potential members of the MCU Sinister Six, is the Ultimate Comics version.
This team was made up of Sandman, Doctor Octopus, Kraven the Hunter, Electro, and the Green Goblin. All of these characters have appeared in Spider-Man movies somewhere along the way, or are about to. The Vulture joins the team later, adding another existing movie piece to the Sinister Six puzzle.