Ironheart, also known as Riri Williams, is coming to the MCU in her own Disney+ series, but it's too early for Iron Man's other potential replacement, Iron Lad, to get the same treatment. Ironheart was announced alongside a profusion of other Marvel content during Disney's Investor Day webcast on December 10, 2020. Dominique Thorne is set to play the titular character, but little else has been revealed about the series. Riri was first introduced to Marvel Comics in 2015, and is a 15-year-old girl genius who builds her own suit of armor modeled after Tony Stark's.
While Ironheart will be MCU's successor to Iron Man (Robert Downey Jr.) after his death in Avengers: Endgame, she is not the only young Iron Man-inspired character in Marvel Comics. Iron Lad, or Nate Richards, is a 16-year-old version of the villainous Kang the Conqueror, plucked from his timeline by his adult self. Horrified by Kang's evil deeds, Nate vows to change his future and defeat Kang. He assembles the Young Avengers and constructs his own Iron Man suit, becoming a hero in his own right as Iron Lad.
The MCU appears to be setting the foundation for its own version of the Young Avengers, but Nate Richards is notably absent from the potential lineup, with Riri seemingly taking his place. Indeed, it appears his origins are too bound up with characters who have not yet been introduced in the MCU, making Ironheart a better fit to succeed Tony Stark.
First and foremost, Iron Lad is a young version of a character who has not yet been established in the MCU. Kang the Conqueror will be introduced in Ant-Man and the Wasp: Quantumania, but the extent to which he will be featured is unknown. He could still be barely set up as the "big bad" of Phase 5, and introducing spin-off characters like Iron Lad before fully fleshing out Kang himself would be too confusing. Additionally, Iron Lad's given name, Nathaniel Richards, comes from Reed Richards' father. Reed Richards and the rest of the Fantastic Four will also get their own MCU film in the future, but setting up Nate along with the team itself could make the movie feel overstuffed.
Riri Williams' origins do not rely on other characters in the same way as Nathan's. She is a self-made engineering prodigy who is later mentored by Tony Stark to become a superheroine. While Stark cannot mentor her in the MCU, her origins could be easily altered for the Disney+ series. The original Iron Man's death could inspire her to build the armor and attempt to fill the void he left behind. Her relatively simple origins require relatively little exposition in comparison to Nate's, making Riri a smarter choice to be Iron Man's successor.
Although Nate Richard's story may be too complex to fit the MCU, a very different version of Iron Lad could take his place. Harley Keener's (Ty Simpkins) appearance at Iron Man's funeral despite only having a small role in Iron Man 3 could be a clue that audiences have not seen the last of him. Stark already gave him some of his advanced technology, which he could use to build an armored suit for himself and take on the Iron Lad title. If Keener were to appear in Ironheart, having two competing Iron Man replacements around could be an interesting plotline for the show to explore.
