WandaVision: 10 Characters Who Could Be The Mysterious Aerospace Engineer
4. Blue Marvel
Introduced to the comics as recently as 2008, Adam Brashear is a relative newcomer to the world of Marvel, but his history actually spans as far back as the 1960s. A former child prodigy, with a Ph.D. in electrical engineering, this character certainly has the scientific background to be Monica's engineering friend.
His relationship with her in the comics only solidifies his claim. After being hit with a blast of radiation during an experiment, Adam was given super powers including heightened strength, the power of flight, and the ability to manipulate matter on a molecular level. He then took on the moniker of Blue Marvel, and went on to serve with Monica as part of The Ultimates (no relation to the alternate universe).
When his teammate found her life threatened by anti-photons, Adam was able to not only heal her, but actually make her powers stronger in the process. The two have quite the history in the comics which could easily translate into WandaVision.
Even this exact story could be adapted by the MCU. Darcy confirmed that Monica is in trouble, and probably can't afford to go through the barrier again. However, she is almost certain to head into Westview once more, and it could be Adam that takes this potential problem and turns it into Monica's powers. Alternatively, it could be the exposure to the barrier's CMBR that ultimately gives both Adam and Monica their powers.