As one of the first superheroes ever created, Superman has long been an influential figure in the superhero genre and he has inspired many other characters. The Amazon Prime show Invincible adapts a comic clearly inspired by Superman. While they are similar characters, Superman and Invincible would make for a fascinating matchup should the two ever fight.
Although Omni-Man severely injured Invincible in their climactic battle, Invincible would not have the same hesitancy to fight Superman that he did when it came to fighting his own father. Though both characters have superhuman strength and abilities because of their alien DNA, the specific differences in their backgrounds and powersets would be the determining factors in a fight between Invincible and Superman.
Invincible
Lack Of Weaknesses
Superman has possibly the most famous weakness in the entire superhero genre; pop culture has even made the word "Kryptonite" synonymous with weakness. But Superman also has other, less iconic flaws such as his vulnerability to magic.
Conversely, while Invincible does have some minor vulnerabilities, such as extreme sound, he mostly lives up to his name. While Invincible could track down some Kryptonite to stop Superman, the Man of Steel would have to hope that he beat Invincible in a straight-up fight without any clear weaknesses to exploit and gain the upper hand.
Viltrumite Cells
Despite the massive amount of damage that Invincible receives in his fight with Omni-Man, he survives the battle and is able to recover thanks to the incredible regeneration of his Viltrumite cells. Even though he is only half Viltrumite, the cells are still so powerful that he essentially is truly invincible.
While Superman is often able to physically overpower his enemies into submission, Invincible's nearly indestructible genetic makeup would give him a fighting chance against anyone — even an adversary as powerful as Superman.
Not Dependent On The Sun
Unlike Superman, who is dependent on the yellow sun for his abilities, Invincible's strength comes from his Viltrumite genetics. Because of this, the Viltrumites have shown the ability to dominate people on planets across the entire universe.
This key difference between the two heroes could greatly impact their fight depending on where it took place. If Invincible was able to take the fight to a location that was not under a yellow sun, he would easily be able to defeat Superman within a matter of seconds.
Trained By Omni-Man
Raised by Jonathan Kent and Jor-El, Superman was trained to be earth's savior. Invincible had the exact opposite experience as he was groomed to become earth's enslavers, unbeknownst to him. While he resisted this purpose, Omni-Man pushed him to his absolute limits and challenged him to reach his full potential.
Omni-Man is an alternate version of Superman, clearly playing off of that archetype. Because Invincible was trained and raised by someone with that powerset and mentality, he has had to quickly learn how to maximize his powers, which would give him the best chance in a fight with Superman.
Superman
Variety Of Powers
While Invincible's powers are mainly his abilities of flight, strength, and invulnerability, Superman has a much broader and more varied powerset, including multiple different ranged attacks.
In the many evil Superman arcs, his heat vision is often shown to be an intimidating and nearly unstoppable attack. Even if Invincible figured out a way to defend against one of Superman's attacks, he has many other options to counter with. Additionally, he would be able to stay out of Invincible's striking distance and still attack with his heat vision or superhuman breath.
Speed
While Invincible is undeniably fast and can fly at an impressive top speed, Superman is next level fast, earning the reputation for being faster than a speeding bullet. He is often shown to be in the same class as speedsters such as the Flash, even if he is a step or two behind.
Superman's speed would definitely give him the advantage over Invincible as he could always stay one step ahead and keep Invincible on his heels throughout the fight. Invincible is fast enough that he would not be completely overwhelmed, but he would find himself fighting an uphill battle as a result of the disparity in speed.
Stronger
More powerful than a locomotive, one of Superman's defining powers has always been his superhuman strength. Invincible is certainly strong and demonstrates this time and time again, but his strength simply cannot compete with that of Superman.
Many of Superman's best villains in DC Comics, such as Darkseid and Doomsday, are among the strongest beings in the universe and yet Superman is able to go toe-to-toe with them. Invincible showed that he could take a punch from Omni-Man, but Superman would clearly be able to physically overwhelm Invincible.
Experience
In many ways, the first season of Invincible has served as the origin story for the character, establishing him as a young and inexperienced hero. While Superman also has a great origin story, he has also had far more time to gain experience and grow as a hero.
After defeating as many villains and adversaries as Superman has, he would have a strategical advantage over Invincible. Superman would easily be able to exploit the young hero's lack of experience and cause him to make a rookie mistake. With an advantage in terms of both superpowers and strategy, Superman would be able to defeat Invincible in a fight.