Warning! This post contains spoilers for Black Widow
Who does Julia Louis-Dreyfus' Valentina Allegra de Fontaine work for in the MCU? These are the Marvel characters who may be behind Val's appearances in Black Widow and The Falcon and the Winter Soldier. The disbandment of the Avengers in Captain America: Civil War, plus the losses they experienced in Avengers: Infinity War and Avengers: Endgame, are bound to create a power vacuum that will attract new heroes as well as new villains. The world needs a team of defenders to keep global threats at bay, and people like Valentina Allegra de Fontaine understand the hidden potential in this necessity.
There are countless teams in Marvel comics apart from the Avengers, but the ones that are most likely to appear next in the MCU are the Young Avengers, the Dark Avengers, and the Thunderbolts. The latter two consist of villains and anti-heroes such as Mac Gargan, US Agent, Baron Zemo, and Red Hulk — all of whom have appeared in the MCU some way or another. While their origins and motivations often vary, they always have always a clear leader, and Valentina de Fontaine may be the one who plays that role in the MCU.
Val has little to do with the creation of super teams in the comics, as she's too busy being a double agent for S.H.I.E.L.D. and HYDRA or acting as Madame Hydra. The MCU is setting her up to be the villain equivalent to Nick Fury — an influential mastermind who assembles a crew of heroes (or anti-heroes) to fight the battles that nobody else could. However, Val mentions she needs a raise in the post-credits scene of Black Widow, which suggests somebody else might be pulling the strings. Of course, Val could have been joking, but a future MCU title could reveal that one of these well-known characters is actually employing Valentina to do their bidding.
Norman Osborn is best known as Spider-Man's archenemy, the Green Goblin. Osborn's other famous identity is the Iron Patriot, a public persona he assumes to gain the trust of the country and hide his crimes behind a superhero facade. As an evil mirror to Tony Stark, the rich owner of Oscorp leads the Dark Avengers, which is a group of supervillains disguised as the replacement of the Avengers. The MCU's Norman Osborn could be aiming to use a twisted version of the Avengers to intimidate anybody who becomes an obstacle for his shady business or to earn political influence. His wealth would allow him to afford such an effective recruiter as Valentina Allegra de Fontaine and finance the Dark Avengers' operations without any problem.
Wilson Fisk aka Kingpin is the most powerful mafia boss in Hell's Kitchen. He often comes to blows with Daredevil and Spider-Man but always manages to find a way back into the criminal underworld. With Valentina Allegra de Fontaine sending Yelena Belova to kill Hawkeye at the end of Black Widow and Echo making an appearance in the Hawkeye Disney+ show, there's a possibility that the Kingpin will also appear as a villain to Clint and Kate Bishop. In fact, he could be the one who assigns Valentina her missions. Like Norman Osborn, Kingpin's wealth and influence allow him to put in progress ambitious plans like forming his own version of the Avengers.
Nathaniel Richards, better known by his alias "Kang the Conqueror," is currently at the center of most MCU theories due to Jonathan Majors' upcoming MCU debut in Ant-Man and the Wasp: Quantumania and multiple Kang hints in Loki. Kang or any of his other identities (like Mister Gryphon or Immortus) could employ Valentina Allegra de Fontaine to unite Earth's Deadliest Anti-Heroes in order to further his plans of conquest. Drastic decisions like sending Yelena to kill Hawkeye could change the course of history, which might be precisely what the time-obsessed Kang is wishing for.
A mention of Doctor Doom in the MCU is only likely after the Fantastic Four have been introduced, but since Valentina Allegra de Fontaine's recruitment tour may need some time to be fully completed, the mastermind behind the creation of the Dark Avengers could eventually be revealed to be Victor von Doom. If Norman Osborn and Kingpin can afford to form their own teams, Doctor Doom could easily set up multiple teams of Dark Avengers all throughout the world if he wanted. The power of the ruler of Latveria knows no bounds, and not even Valentina could grasp the real dimensions of who she's working for.
Valentina assembling a team for Baron Zemo would be the kind of twist the MCU is known for. When Val provides John Walker with his US Agent suit at the end of The Falcon and the Winter Soldier, she acknowledges the fact that Zemo got rid of the last surviving Flag-Smashers. This doesn't confirm Val and Zemo have an active work relationship, but it could be that the always unpredictable Zemo has tasked Val with assembling the Thunderbolts while he's at the Raft.
General Ross seems like the last MCU character to work alongside a figure like Valentina Allegra de Fontaine, much less order her to assemble a team of uncontrollable superhumans. However, Ross's previous experiences with the Sokovia Accords may have convinced him that the best way to keep superheroes in check is by leading his own team. In the comics, Ross becomes the Red Hulk, whose incredible power and advanced intellect could be an amazing asset for whichever team Val is putting together.
Marvel's Contessa Valentina Allegra de la Fontaine is often associated with organizations like S.H.I.E.L.D. and HYDRA but also with J.A.N.U.S. and Leviathan. The MCU could choose to revive a faction of the former two, proving HYDRA's motto, "cut off one head and two more shall take its place," correct. Or perhaps a future movie or series could replace the MCU's secret organizations with the "Dark Illuminati" J.A.N.U.S. or the Soviet-originated Leviathan. Any of these organizations could aim to control their own version of the Avengers with Val spearheading the project.
Not only do Valentina Allegra de Fontaine and Nick Fury play a similar role in the comics, but they're also a recurrent couple. The MCU could feature Nick Fury passing on the torch to Valentina the same way Natasha Romanoff passed on the baton to Yelena Belova. Fury's wish to create a new team of Avengers could be well-intentioned, only for Val to manipulate the new squad into becoming villains.
One of the most likely possibilities is that Valentina Allegra de Fontaine was just joking when she said she needed a raise in Black Widow, and that it's her original idea to seek and recruit new superheroes into her team. Val is arrogant and ambitious, so it wouldn't be far-fetched to think she answers to no one. This would make her more resourceful than Nick Fury and perhaps more villainous than any MCU antagonist she could get her hands on, as she's willing to lie and manipulate her recruits in order to satisfy her whims.
