Warning: this article contains spoilers for Hulk #1!
Tony Stark just revealed his Hulkbuster armor has a brand new weapon, as Iron Man attempts to take down the Hulk and prevent Bruce Banner leaving the planet. Tony Stark has a suit for everything, from deep-space exploration to the King in Black, but one of his most famous is the Hulkbuster, a suit he designed against the eventuality of the Hulk going on a rampage and needing to be taken down.
The Hulkbuster has only appeared twice in the MCU; once in Avengers: Age of Ultron, when it was successfully used to put the Hulk to sleep after a lot of property damage, and again in Avengers: Infinity War - when it was actually worn by Bruce Banner. But there have been numerous versions in the comics, with Stark constantly upgrading its weaponry in an attempt to figure out just how to contain the Jade Giant. No Hulkbusters have been especially successful, because the Hulk's incalculable rage is pretty hard to counter, but in Hulk #1, Tony thinks he may finally have a weapon to even the score.
Hulk #1, by Donny Cates, Ryan Ottley, Frank Martin, and VC's Cory Petit reveals just how powerful this latest Hulkbuster really is, introducing a phenomenal new weapon. Tony Stark uses drones to launch a shower of what he calls "adamantium nanoparticle shrapnel." The unbreakable adamantium shards are sharp enough to burrow into even the Hulk's skin, with nano-programming triggering them to form any shape Stark wishes. In this case, he chooses a cage in an attempt to imprison the Hulk.
This is easily one of Iron Man's most effective weapons, and no doubt it could be deployed against cosmic threats such as Thanos as well. Adamantium is a rare metal, but interestingly it seems to be becoming increasingly common in the Marvel Universe right now, with the X-Men on Krakoa possessing a sizable reservoir they use to re-coat Wolverine's bones whenever he's forced to go through their Resurrection Protocols. It's difficult to say how adamantium has become so common, but it makes sense for Stark to be one of the few people to find new ways to weaponize it.
Sadly, while Tony's new Hulkbuster weapon succeeds in trapping Hulk, he underestimates what it will take to stop Bruce Banner. Now 'piloting' his gamma form, Bruce willingly tears off his own arm to escape, defeating Tony shortly after. Despite the loss, Iron Man's latest weapon is a huge improvement on the Hulkbuster's weapons systems, and a vicious weapon to wield against anyone, let alone a former ally. The Hulkbuster may have failed to stop the Hulk, but adamantium shrapnel is no joke, and Iron Man fans will be hoping this weapon makes a comeback in future stories.