Since its creation in the radio serial The Adventures of Superman in 1943, followed by its introduction in DC’s comics in 1949, kryptonite has been the main weakness of the Man of Steel. In a true case of bitter irony, the one remnant of Superman’s home planet is his primary weakness and can kill him if he or any other Kryptonian is exposed to it for too long.
Over the years, between comic page and film, kryptonite has had many appearances and many more iterations in different color forms, with differing effects. Despite its form, kryptonite continues to be the deadliest weapon to use on Superman. Here are the ranked deadliest uses of kryptonite.
10 GREEN KRYPTONITE NECKLACE
Kryptonite-to-skin contact has always been a basic deadly use of the rock. As seen in 1978’s Superman: The Movie and The CW series Smallville, Kal-El has always felt at his weakest when kryptonite touches his skin.
While Batman keeps a kryptonite ring simply to level the playing field, making Superman weak enough so Batman can hurt him, those who place the deadly rock around Supes’ neck are in it to seriously hurt – if not, kill – him. It makes him so weak, Superman is unable to find the strength to just lift the necklace off his neck.
9 KRYPTONITE KNIFE/SWORD/SPEAR
It’s safe to say that any weapon forged from green kryptonite is one of the deadliest uses, but sharp blades, in particular, are of special danger to Superman and Kryptonians.
After all, not only does the green blade weaken Supes but it can also impale him and be kept in his body to keep him dead. If it’s a make-shift blade that can be broken off and left inside the body, it is all the more deadly. However, as long as any Kryptonian is under a yellow sun, as soon as the blade is removed, they can heal.
8 SILVER KRYPTONITE
Originally introduced on the CW’s Smallville and made canon in Superman/Batman #46, silver kryptonite has the ability to infect a Kryptonian in such a way as to make them suffer from paranoid delusions, altered perceptions, and loss of inhibitions.
This doesn’t sound as deadly as green kryptonite; however, a Kryptonian like Superman could be very dangerous to everyone around him if he believed they were enemies such as Doomsday. Even though its infection of Clark may only have been coincidental in the comics and TV series, using it intentionally would prove deadly.
In 1959, writers went a step further and decided to make a villain whose heart had been replaced by machine and kryptonite. Once known as John Corben, Metallo soon grows to hate Superman, not just because the villain sees the hero as competition for Lois Lane’s affections, but because Metallo also believes Kal-El was sent to invade Earth and enslave mankind.
Corben’s human mind may be in Metallo, but the rest of him is a machine and his evil ways grow even more dominant. He also has the ability to shoot kryptonite beams at Superman to weaken and possibly kill him.
6 BLACK KRYPTONITE
Although black kryptonite first appeared in its usual form in 2005’s Supergirl #2, most can say it technically first appeared in the 1983 film Superman III. The film’s villains manufacture a form of kryptonite by filling in an unknown element with tar.
The rock they give Superman is green but its effect is the same as black kryptonite: Separating Superman into two beings – one evil and one good. This was used by Lex Luthor (under guidance by Darkseid) to separate Supergirl to attack her cousin. Again, not seemingly as deadly as green kryptonite but if a truly evil Superman was unleashed on an unsuspecting city, the destruction and death would be immeasurable.
5 KRYPTONITE MAN
Although a younger version was first introduced in Superboy #83, the infamous Kryptonite Man first appeared in Superman #299. There are different iterations but the most deadly has to be the one man whose skin – after passing through a gaseous cloud of kryptonite – turned green and started to radiate kryptonite rays.
It’s an obvious but very necessary invention to have a villain with such a deadly power. Surprisingly, Kryptonite Man is not a major A-list villain for Superman and has been sparsely used over the years. The reason for this is most likely because he’s practically invulnerable to Superman and could kill the man of steel just by being in close proximity to him.
4 GREEN KRYPTONITE BULLET
The kryptonite bullet has been a legendary use of the deadly element ever since the creation of kryptonite. If a bullet lodges in Superman’s body, it’s difficult to extract and can leave him dead as a result.
Whether used in live-action series or in the pages of comics, the kryptonite bullet has the speed to kill or severely injure any Kryptonian. Once the bullet is either nearby or in a Kryptonian, they would be too weak to avoid or remove it.
3 ANTI-KRYPTONITE/SLOW KRYPTONITE
This kryptonite may have two different names but the effect is the same: The death of all humans. Anti-Kryptonite and Slow Kryptonite – manufactured by Metallo – have the same effect on humans that green kryptonite has on Kryptonians. While this sounds fine for Superman, Supergirl, Krypto, Zod, Jor-El, and all other Kryptonians, it would mean genocide for the entire human population.
As proved in Green Lantern #123, Superman has a case of it in his Fortress of Solitude and Hal Jordan threatened to use it on a powerless Zod, which would have killed him. Also, Anti-Kryptonite serves as a power source for Superman’s Earth 3 evil counterpart, Ultraman – a true nightmare of a villain as he has all of Supes’ powers but none of his morality.
2 GREEN KRYPTONITE-INFUSED DOOMSDAY
In 2003’s run of Superman/Batman, the two superfriends decide to rid the Earth of all kryptonite. In their search, they come across a member of Amanda Waller’s Last Line team to defend Earth. She infused Josh Walker with Doomsday DNA and infused it with kryptonite, transforming the All-American Boy into a Doomsday with kryptonite protrusions.
The mix of the deadliest element and the only being to kill Superman would be the ultimate lethal weapon against Kal-El. Unfortunately, this creation hasn’t been used since Waller’s science experiment, due to Walker’s humanity being reached through familial love. However, if this was absorbed into the real Doomsday, there would be big trouble for Supes.
1 GREEN KRYPTONITE GAS
It’s been used in comics, animation, and TV series, but the most recent and memorable appearance of kryptonite gas was in the 2016 film Batman v Superman: Dawn of Justice, as Batman creates and uses the lethal toxin to help weaken and possibly kill Superman.
The reason this would be the most deadly use of kryptonite is because of its gaseous form. Unlike a blade or bullet, kryptonite gas is difficult to remove as it would be inhaled into Superman’s lungs and could kill him. In the film, Supes is somehow able to survive two kryptonite gassings; however, it should weaken him long enough for most villains to deliver a killing blow.
As Superman's greatest weakness, kryptonite has been reconfigured countless times in an attempt to kill Kal-El. Here are its deadliest uses.