In the film, we saw Tony Stark, aka Iron Man, save the world by sacrificing himself when he wielded the power of the Infinity Gauntlet and used the stones to decimate Thanos and his crew. While speaking at the Gene Siskel Film Center gala, Downey Jr. suggested the RiRi Williams, aka Ironheart, should be introduced in the MCU.
In Endgame, we saw Steve Rogers hand off his Vibranium shield to his buddy Sam Wilson, making him the new Captain America. The same can’t be said for Stark and the mantle of Iron Man, though. While his best friend, James Rhodes, has his own suit of armor and Gwyneth Paltrow’s Pepper Potts presumably not coming back, there is a huge void to be filled with Iron Man’s death.
RDJ made the suggestion of RiRi Williams replacing him in the Marvel Cinematic Universe after he was introduced to attendees by Eve Ewing, who is the current writer of the Ironheart comic book series.
For those who don’t know who RiRi Williams/Ironheart is, she was created by writer Brian Michael Bendis and artist Mike Deodato. While attending MIT, the teen prodigy built her own Iron Man-like armor that uses an A.I. modeled after Tony Stark’s consciousness that assists her in controlling her suit while mentoring her while he recovers.
As for her joining the MCU, that’s totally up to Marvel Studios’ head Kevin Feige, who has a lot on his plate at the moment. With the upcoming Spider-Man: Far Home film closing out phase three, it’s time he to start planning what’s in store for the fourth phase. BUT we are sure Robert Downey Jr.’s word goes a long way, so we wouldn’t be shocked if Ironheart does eventually find herself fighting alongside the likes of Thor, The Hulk, Scarlet Witch, and others.