While the Hulk and the Fantastic Four have a complicated relationship within Marvel Comics continuity–with Bruce Banner being good friends with Reed Richards and the Hulk being a fairly-regular opponent to the Thing–another wrench has been thrown into the works as Marvel’s First Family just introduced a weapon that could actually kill the Hulk should that be deemed necessary.
Bruce Banner aka the Hulk and the Fantastic Four are incredibly similar in that every single one of them began their lives as humans until they were mutated by an outside force that granted them superhuman abilities. The difference, however, is that Bruce Banner became the Hulk after he was blasted with gamma radiation while the Fantastic Four got their powers after being engulfed in cosmic rays–and that is an important distinction especially in regard to the Hulk. Due to his unique mutation through gamma radiation, cosmic rays are essentially Kryptonite to the Hulk, which was proven true during the Green Goliath’s battle with the U-Foes during the Immortal Hulk series. If the Hulk is shot with cosmic rays, he will wither away and die. While that is bad enough, one weapon introduced in the Fantastic Four takes things one step further.
In Fantastic Four #48 by David Pepose and Juann Cabal, Sue Storm is facing off against Oubliette after the villain broke into the Baxter Building during a full-on assault against the Fantastic Four. At this point in the wider Marvel Universe, the world is being judged by a Celestial known as the Progenitor–an event that could mean the end of the world. Due to this immense threat, Reed Richards has locked himself inside an isolation chamber so that he could think of a solution without interruption or distraction. However, this left him very vulnerable, which is why Oubliette chose now to strike. During the villain’s fight with Sue Storm, Oubliette pulls out a pistol and shoots Sue in the shoulder. What the Invisible Woman quickly learns is that this isn’t a normal pistol, but one that turns the person it shot into solid gold–changing their molecular structure in order to do so. The reason these bullets have this capability is that they, and the gun itself, were treated with none other than cosmic rays.
Not Even Death Could Save the Hulk from the Fantastic Four’s New Weapon
If the Hulk were to be shot with this gun (a weapon that is now in the hands of the Fantastic Four following Oubliette’s defeat at the end of this issue) then he would be poisoned by the cosmic radiation that would be surging through his bloodstream–and the fact that the bullets were treated in cosmic rays ensures that they would pierce the Hulk's skin. Plus, the bullets would transform the Hulk into a gold statue as they would change his entire biological makeup just as they did to Sue Storm. While Sue was able to use her powers to fight off the effects, the Hulk wouldn’t be able to do so since he would be suffering from the deadly effects of the cosmic rays, and the fact that he’d be turned to gold means he couldn’t just die and come back as he did in the Immortal Hulk since he wouldn’t have a viable body to re-inhabit as his body would be an immobile gold form infected by deadly cosmic rays.
In short, if this gun were to be used against the Hulk, his healing factor along with any other powers he had through his gamma mutation would be permanently neutralized while he would slowly turn into gold–becoming a twisted monument to his own greatest weakness. Now that the Fantastic Four have possession of this weapon, they have the ability to take down one of the greatest power-houses in the world should they ever need to in the future, as it truly is the perfect Hulk-killing gun.