As in the comics, Kal-El's powers are depicted as being superior to other Kryptonians, due to his spending a far greater period of time exposed to Earth's yellow sun and atmosphere, though some have an advantage over him in terms of combat experience (e.g. Zod, Faora and Nam-Ek).
Superman derives his power from the yellow sun of Earth. Forced under a red sun akin to the red sun of his homeworld, Krypton, or exposed to red sun radiation, Superman rapidly loses his powers, reverting to the stature of a normal human.
Zod, though, is even stronger than Superman because he has absorbed less of Earth's sun than Kal-El. Zod overpowers Superman from the first time that the two opponents face off. Superman's sheer grit is the only thing that ultimately allows him to emerge victorious.
He is an Kryptonian hunter. He has enough skills to beat Superman either on earth or in the Phantom Zone. He was created by Jor-El. Rogol thinks that the planet consists of citizens that are a virus to the galaxy.
Though Superman usually finds a way to get the upper hand over Zod, the popular villain has still managed to beat the Man of Steel on several occasions, and has also outmatched him in other ways. As a highly experienced Kryptonian general, Zod has years of tactical and combat experience under his belt.
In the first stories about Superman's origins, all Kryptonians possess on their homeworld the same powers Superman has on Earth. In later depictions, their abilities are attributed to the differences between Earth's gravity and that of Krypton and the different radiation of the stars they orbit.
Captain Atom has proven in past battles that he is stronger than Superman and has better fighting skills. He can also weaponize red sun radiation, which can weaken Superman like Kryptonite and magic. His sometimes uncontrolled nature has earned him a reputation as one of the most dangerous DC heroes.
This General Zod (born Avruiskin) is a Russian who was affected before his birth by his parents' exposure to Kryptonite radiation. As such, he is empowered by red sunlight and weakened by yellow, the opposite of Superman.
In summary, Supergirl has significantly more potential than Superman, but whichever Kryptonian has more yellow star radiation will have access to even greater powers. Ultimately, neither hero is limited by their build, their age, or even their training.
Strength. Doomsday possessed enormous superhuman strength that is significantly greater than Superman and at one point this enabled him to effortlessly stand his ground against the entire Justice League, including Superman and Orion.
It's important to note that the rules around worthiness had been temporarily suspended to allow this to happen. As soon as the fight was over, Superman couldn't lift the hammer anymore. However, under normal circumstances, without any weird interference, Superman is worthy of Mjolnir.
Even though Superman is often considered the most powerful character in the DC Universe, Shazam definitely comes close, and he can even beat the Man of Steel. And with a massive power upgrade, there's no question that Shazam can meet Superman blow for blow—despite the upgrade's terrible side effects.
Green kryptonite weakens Superman and other Kryptonians, and is fatal with long-term exposure. Kryptonians under green kryptonite's effects experience severe muscular weakness, usually to the point of collapse, and excruciating pain, with both conditions progressively intensifying.
Superman is very vulnerable to telepathy. This is going to make defeating Martian Manhunter impossible for the Man of Steel. In fact, it would make it hard for anyone to defeat Martian Manhunter, since he could puppet Superman around from afar.
There's no question the Hulk is a near-indestructible force who comes out on top in almost all of his battles of pure strength. However, against Superman, he's outmatched. While Hulk's strength might rival that of the Man of Steel, Superman's other abilities give him a considerable edge against his opponent.
Superman has accomplished some amazing things, but one of the greatest is the fact that he's been able to triumph over Darkseid. Darkseid is the God of Evil and the lord of Apokolips. He's led his forces in a war against the New Gods of New Genesis for ages and has attacked the Earth many times.
General Zod has the same powers and strength as Superman, but he is a trained military genius, with Superman raised a farm boy. Despite this, Superman has beaten Zod, and there was even one point where he killed the General, one of the few times Superman broke his no-kill rule.
So, no, Superman can't breathe in space, because the term is meaningless in the conditions being described, but he can survive for a long, long time without taking a breath. Couple that with durability, super speed, and flight, and Clark Kent rarely has to worry about running out of breath.
Due to the success of living in a sustainable atmosphere with little to no complications, a Kryptonian's body can remain in the same physical state for as long as possible. This can enable them to live well into their hundreds to even thousands of years with every detail of their appearance remaining unchanged.
Shazam, The Flash, and more superheroes who are much stronger than Superman. Many canon storylines have depicted the powerful survivor from Krypton getting defeated in battles. Furthermore, it is cited that the superhero does not push himself to the extent of his powers, which is the reason for his defeat.
The killing of Zod gave a reason for the character never to kill again. Superman falling to the ground and screaming afterward — I don't think that was originally in the script, but I wanted to show the pain he had.
While Superman's reputation as DC's strongest hero is important to the themes that make him work, Darkseid isn't just more powerful, he's a higher level of being.
