Captain America: Brave New World is about to introduce a game-changing element to the Marvel Cinematic Universe, and it isn't the Red Hulk. At San Diego Comic-Con 2024, it was confirmed that Captain America: Brave New World would introduce the metal adamantium into the MCU. Adamantium is best known as being the metal that is bonded with Wolverine to give him his metal skeleton, though the fictional metal predated Wolverine's creation as it was first introduced in The Avengers #66 from July 1969 by writer Roy Thomas and artist Barry Windsor-Smith and Syd Shores as the plating for the villain Ultron.

The MCU version of adamantium will be derived from the Celestial head Tiamut, last seen in Eternals, answering the question every Marvel fan seems to bring up with each new MCU property: "How come nobody mentions the giant head in the Indian Ocean?" While Deadpool & & Wolverine did feature Wade Wilson wielding adamantium katanas and Wolverine himself, that film largely took place outside of the MCU sacred timeline and in the wider Marvel Multiverse. The Marvel Cinematic Universe's introduction of adamantium into the franchise's main story as a new metal being discovered is a game changer for the series, but also one that might give context to the X-Men's existence, or lack thereof, in the MCU. It also could have ties to events centered around Daredevil, Black Panther, and the Hulk. Here is why adamantium's arrival in the MCU is such a big deal.

If Adamantium Is New, How Can Wolverine Exist Within the MCU?

While Ultron might have been the first character to wear adamantium, it is Wolverine who most audiences associate with the material. The MCU even subbed out Ultron's metal platting from adamantium to vibranium. Adamantium is bonded with Wolverine's skeleton and claws as part of the Weapon X program. Audiences saw this event depicted in both X2: X-Men United and X-Men Origins: Wolverine. Yet, with adamantium being new to the MCU, it certainly means a significant change for one of their most prominent characters ahead of their MCU debut.

A recent trailer for Captain America: Brave New World, which features the same scene showcased at San Diego Comic-Con 2024, sees Harrison Ford's President Ross say, "When the Celestial mass emerged, we squabbled over it. What was found inside that island was the discovery of the millennium. I present to you...adamantium."

According to the Marvel Cinematic Universe: An Official Timeline, the Eternal Sersi turns Tiamut to stone in Fall 2025, two years after the Blip in Avengers: Endgame and a few months after Sam Wilson suited up as Captain America for the first time. Ross' quote puts a firm timestamp on when adamantium became part of the Marvel Cinematic Universe, making it a recent phenomenon. If Tiamut is the sole source of Adamantium, that means it did not exist within the MCU until recently and could not have existed prior to 2025. This means that if Wolverine existed within the MCU, he could not have been bonded with the metal until after Eternals.

What This Means for Wolverine

If this is the case, this would certainly change a lot of Wolverine as a character since getting his metal claws would be a new experience. With Weapon X being tied to the loss of Wolverine's memory, that also means that his memory loss would be a relatively recent event, likely fresh to the character if and when he meets the Marvel Cinematic Universe version of the X-Men. Currently, no suggestion of Wolverine or the rest of the X-Men currently exists, but the idea of mutants in the Marvel Cinematic Universe does.

Could Marvel Retcon This?

If Marvel Studios did want to reveal that Wolverine had adamantium grafted to his skeleton by Weapon X before Tiamut emerged, they would have to retcon adamantium's origin. That isn't out of the realm of possibility, as the MCU already did similar retcons around vibraniums history. Captain America: The First Avenger revealed that Captain America's shield was made of vibranum, which was then described as the rarest metal on Earth, and it was all the United States government had access to.

Similarly, Avengers: Age of Ultron and later Black Panther established that others seemed to know about Vibranium, even if they didn't know all the secrets of Wakanda. Black Panther: Wakanda Forever even retconned that Wakanda isn't the only source of Vibranium, as a second meteorite hit the Atlantic Ocean and led to the creation of the underwater civilization of Talokan.

While the MCU had a bit more leeway around vibranium, given that there was no hard date for the emergence of the metal in the MCU timeline, that doesn't mean there aren't ways around it for adamantium. With adamantium coming from the head of Tiamut, it suggests that during the time the Celestial was growing inside the Earth, tiny samples of the indestructible metal might have emerged to the surface and been discovered to create the Weapon X program. There is also the chance that Sersi, in her 5,000 years on Earth, might have made small samples of the adamantium throughout history that were left unaccounted for and collected over the years.

That might explain what makes Wolverine unique: the tiny bit of Adamantium discovered before Tiamut emerged was grafted onto Wolverine, making him one of a kind, just like how Captain America's shield was the only sample of vibranium outside of Wakanda. The emergence of adamantium in Captain America: Brave New World could be true to the rest of the world of the MCU, but that doesn't mean there couldn't have been small samples of it left around over the years. Yet there are a few immediate ways that this could impact the MCU that have nothing to do with the X-Men.

Adamantium Might Be Important for 'Daredevil: Born Again'

Wolverine might be the figure most commonly associated with adamantium, but he isn't the only one. Daredevil: Born Again, the MCU project that follows Captain America: Brave New World on the slate, is set to feature a character with adamantium grafted to his skeleton: Bullseye. Created by writer Marv Wolfman and artist John Romita Sr., Bullseye has been one of Daredevil's most iconic enemies since he debuted in Daredevil #131 in March 1976. In Daredevil #197 in April 1983, it was revealed that most of Bullseye's bones were enforced with adamantium after a bad fall.

Bulleye surgery to have the adamantium procedure was done by Professor Kenji Oyama, who is the inventor of the adamantium bonding process that later created Wolverine (Wolverine's procedure was implanted using stolen and incomplete notes on the bonding process, with the character only surviving due to his healing abilities). Kenji Oyama is also the father of Yuriko Oyama, who would later become the X-Men villain Lady Deathstrike.

Kenji Oyama was actually referenced in Daredevil Season 3 as Dr. O, played by Glenn Kubota. He was referenced operating on Benjamin "Dex" Poindexter, the MCU version of Bullseye, to repair his spine after the Kingpin broke it. Daredevil: Born Again has confirmed that the events of the previous Daredevil series are canon to the Marvel Cinematic Universe, meaning the scientists from the comics that created the adamantium bonding process in the comics exist in the MCU.

Wilson Bethel is confirmed to be returning to Daredevil: Born Again as Bullseye, and the reason the series might be coming out after Captain America: Brave New World is because it will follow up on the adamantium plotline. It could be revealed that Kenji Oyama got his hands on some adamantium from Tiamut and used it to finally fix Bullseye, explaining why he emerged after all these years. Even if Kenji Oyama might not appear in Captain America: Brave New World or Daredevil: Born Again, it is a development that Marvel Studios could return to for future projects, possibly tied to when the sacred timeline version of Wolverine does appear.

A Fictional Arms Race in the MCU

The arrival of adamantium in the Marvel Cinematic Universe certainly is coming at an interesting point in the franchise. 2022's Black Panther: Wakanda Forever established the nations of the world were attempting to get their hands on vibranium. While Wakanda had certainly stopped attempts to retrive Vibranium, the United States government discovered a source of the metal under the ocean (thanks to a device they took from MIT student and Ironheart alter ego Riri Williams). This led the nation of Talokan, an underwater civilization ruled by the mutant Namor, to conflict with Wakanda. Namor threatened war with the entire surface world if Wakanda did not bring him Riri Williams. The new Black Panther, Shuri, defeated Namor and promised they would keep the location of Talokan and its Vibranium secret from the rest of the world.

The emergence of adamantium, coming out from the ocean onto the surface, makes for a new robust metal alloy that the nations of the world seem to be able to exploit with free rein. This means that many nations in the MCU might be developing adamantium weapons, ones that, in theory, could damage or destroy Vibranium. The world's nations no longer need Wakanda, but that doesn't mean a target is off their back. Instead, more nations might be emboldened to use their adamantium resources to retaliate against Wakanda. This might force the leaders of the nation to turn to the Talokan for help. It is highly likely that the nation of Wakanda will be watching for the Celestial head Tiamut and adamantium, which could become a plot point for Black Panther 3.

Adamantium might also be used to combat the rising threats of Hulks in the Marvel Cinematic Universe. Since the emergence of Dr. Bruce Banner / Hulk, he has been described as one of the most powerful beings in the MCU. Over the years, more Hulks have emerged, including The Abomiantion, She-Hulk, and now the Red Hulk. With so many Hulks on the loose, various nations might create adamantium weapons to combat this threat. After all, Wolverine made his first appearance in The Incredible Hulk #180 and has been a regular sparring partner of the Hulk. With Wolverine's claws, and by extension, adamantium, one of the few things that can cut through the Hulk's skin as well as damage vibranium, adamantium truly will be a game changer for the franchise.

These developments might take a back seat as the Multiverse Saga collides towards Avengers: Doomsday and Avengers: Secret Wars, which is rumored to be a slight reboot of the MCU, which might just explain the X-Men and adamantium always existed. With Phase 7 of the MCU highly rumored to be very X-Men-centric, introducing adamantium into the MCU now feels like Marvel Studios is teeing up some big plotlines for future movies and Disney+ series. Expect a lot of debates on which metal is stronger, vibranium or adamantium.