WandaVision explains Captain Marvel’s Avengers: Endgame reaction to Thanos. The superhero was missing in action during the events of Avengers: Infinity War, but was called back to Earth by Nick Fury shortly before he was snapped out of existence by the Mad Titan. Captain Marvel arrived early on in Endgame and headed to space with Thor and the remaining Avengers to find and defeat Thanos. However, it wasn’t until the final battle five years later that fans witnessed the full breadth of her rage for the villain. Now that WandaVision has offered further backstory, Captain Marvel’s reaction to Thanos makes a whole lot more sense.
Captain Marvel introduced fans to Maria Rambeau, Carol Danvers’ best friend and fellow Air Force pilot, and her daughter Monica. WandaVision, which takes place post-Endgame, wasted no time in confirming that Maria founded S.W.O.R.D. and Monica followed in her mother’s footsteps. However, Monica was one of the casualties of Thanos’ snap and disappeared while in the hospital for her mother’s cancer treatment. Monica returns to life five years later, but tragically discovers that Maria died from cancer two years after Monica was dusted. Captain Marvel is present for none of this, which explains why Monica seems reluctant to discuss the superhero with others and even bristles at the mention of her.
While Monica and Maria’s fates are tragic on their own, the revelations in WandaVision go a long way to expand upon Captain Marvel’s response to Thanos in Endgame. When she spots him during the final confrontation, her expression is intense and she’s visibly infuriated by his presence. Watching the scene out of context, one may have wondered why Carol was so viscerally irked by the Mad Titan. Of course, wiping out half of the world’s population would have pissed off anyone, but Captain Marvel’s anger seemed more personal.
At this point in the story, five years had already passed and Carol had lost both Monica and Maria. While Thanos had nothing to do with Maria’s death, his snap did kill Monica, which likely devastated Maria. Who wouldn’t be after losing their daughter in such a way? His actions also prevented Monica from being by her mother’s side when she passed away. The mother-daughter pair were effectively robbed of their time together because of the antagonist’s decimation. This would understandably enrage Captain Marvel, who was incredibly close to Maria and thought of her as family. Yes, she had been away for several years, but that doesn’t prevent Carol from caring about her best friend.
Carol probably knew that her friend was grieving the loss of her daughter and was angry with Thanos for taking Monica away from her mother, most especially during her time of need. With Monica (and Carol) gone, Maria had to continue undergoing cancer treatments on her own and died with no family by her side. Surely thinking of the ways her friend suffered incensed Captain Marvel, whose feelings were probably dredged up and much closer to the surface upon seeing Thanos again after so many years of loss. There’s even a chance Captain Marvel was frustrated by the fact that she was also not there when Maria and Monica died and was at least partially angry with herself. Either way, WandaVision is doing a lot in the way of filling in the gaps with regards to Endgame.