For the past decade, Tony Stark (aka Iron Man) has been the leading force of the Marvel Cinematic Universe (MCU) since the character's first solo film in 2008, until his epic conclusion in Avengers: Endgame in 2019. This character relaunched the career of Robert Downey, Jr., a tremendously talented actor with plenty of charisma and ambition. Since the journey of Tony Stark/Iron Man is over, who could take Stark's place?
With Phase 4 of the MCU already underway, there are characters, either older, newer, or more recent, who are capable of taking the mantle from the great Tony Stark. Of course, taking Stark's place is a very tall order to fill, but there are a few candidates already qualified for the job.
Loki, the God of Mischief himself, would appear to be the wrong choice considering that he's been one of the MCUs biggest villains who killed and caused major destruction towards humanity. Tony Stark wasn't always perfect either because, initially, he cared more about his own interests (particularly control over his company, Stark Industries). However, when he realized that the weapons made by his own company were being used by terrorists and evil entities, Stark took responsibility and action, recognizing that he could do more to protect the world.
Despite initially being a villain, Loki transitioned to a hero because he started to care more about humanity, and had love for his brother Thor and the people of Asgard. With his Disney Plus series, Loki has become even more heroic and caring, especially towards Sylvie (a Loki variant). Loki also relates to Stark because both men are highly intelligent, and can come up with clever resolutions to complex problems.
After the widely acclaimed first season of Loki, the God of Mischief needs to be smarter than ever in trying to resolve the dilemma concerning the multiverse (which will be a major ongoing conflict in Phase 4). Loki has also proven that he can become a leader (like Tony Stark was for the Avengers) by helping his brother and the people of Asgard in Thor: Ragnarok. Loki can also lead the members of the TVA (Time Variance Authority) in the right path in season two of Loki, after Sylvie started the multiverse, causing timelines to malfunction.
Another wise choice to take Stark's position is Shuri (who starred in Black Panther). Like Tony, Shuri knows how to use vibranium and advanced technology, and works well with machines. Tony is known for creating cool and efficient Iron Man suits with updated weapons and gadgets. Shuri operates the same way with the Black Panther suits, especially by making them absorb kinetic energy.
Along with the Black Panther suits, Shuri can make more technology that can help not only the people of Wakanda, but the entire globe (this was a major concept in the first Black Panther film). Shuri and her brother, T'Challa, became humanitarians in ensuring their vibranium and advanced tech provided guidance for their African ancestors around the world, especially young children in poor communities, who can use it to do good and form innovative creations.
Tony was also a successful humanitarian and philanthropist, as shown in Captain America: Civil War, when he granted fellowships under his name to students who had inventive technological projects. Shuri shares many of the same passions as Tony when it comes to forming technology that can protect the world.
Peter Parker/Spider-Man would be another exceptional choice to take over from Stark because Tony was a valuable mentor and father figure to him. Peter also enjoys working with tech and is elite in math and science. Peter was used to working alone, but when he met Tony and many of the Avengers in Civil War, Peter has proven to be a team player, especially with Doctor Strange (who appear to work together more in Spider-Man: No Way Home).
Peter took Tony's death very hard in Spider-Man: Far From Home, and it's uncertain if Tom Holland will continue to portray Peter after No Way Home, but his Spider-Man character has grown from a young, vulnerable hero to a stronger and more confident superhero. He could be one of the new leaders for the Avengers, and have assistance from Doctor Strange, Loki, and Scarlet Witch in solving the multiverse dilemma.
The future of Bruce Banner/Hulk is also uncertain (with the possible exception of the new She-Hulk TV series), but he could take Stark's place since Banner and Tony had been friends and colleagues since the first Avengers film. Like Stark, Banner has a passion for science and tech. Banner helped Stark form Vision in order to defeat Ultron. He also helped the Avengers go back in time, as well as form another gauntlet to reverse Thanos' snap in Endgame.
Banner still has plenty to give in terms of story, and Hulk can use more action. He also worked well with Doctor Strange in Infinity War, and Banner can also be part of solving the multiverse situation since he had experience with time travel in Endgame. Hulk could not only bring the Avengers together, but he could reunite once again with Loki (old nemesis turned ally) and Thor (Banner's second best friend). Depending on whether he will need it or not, Banner also looks good in the bulky Iron Man suit (the Hulkbuster should be a last resort if Hulk himself can't physically fight and smash).
It's a major challenge to replace Tony Stark, the godfather of the MCU. While Loki, Peter Parker, and Bruce Banner are highly qualified, Shuri is the best choice to be the new Tony Stark in Phase 4 of the MCU. She has the intelligence and charisma, as well as the expertise since she's knowledgeable in the use of advanced technology and vibranium. Shuri would undoubtedly be a valuable member of the Avengers, not only in terms of providing tech, but in inspiring other women and people of color to become superheroes.