Most of the time, Superman, whether it be Clark Kent or someone else embodying the feel of the Man of Steel, is meant to stand for hope. A Superman analog is intended to hold the good of the world in one person. Of course, that's not to say that evil Supermen like Homelander and Omni-Man don't exist.
One a genetically engineered and unstable superhero working for a billionaire dollar company, the other a world-conquering Godlike being with a half-Viltrumite son, both evil Supermen have committed terrible deeds over the years. The question is: who's the more evil of the pair?
Homelander: Increasingly Unstable Nature
In comparison to everything else, Homelander's done, having an increasingly unstable nature to a lot of people may not seem like the worst thing in the world. After all, when audiences first meet him, Homelander's already got a brutal streak.
Yet when season 2 rolls around, Homelander somehow manages to go from a bad guy to a straight-up supervillain. The worst part is his hallucinations when he imagines things like lasering an entire crowd of innocent people. While it doesn't happen, it sets the stage for later events in season 2 and for more evil to come in season 3.
Omni-Man: Lied To Family And Friends
Like Homelander, lying on the scale of evil is honestly pretty low. For Omni-Man, lying compared to everything else he's done is a minor offense in the large scheme of things. However, it's still worth noting Omni-Man lied to everyone's face about who he was.
For years, his wife, his colleagues and his own son all believed Omni-Man was a peaceful warrior, fighting for the betterment of Earth. In reality, the hero is nothing more than a brutal world conqueror set on doing what his vicious planet requires of him: weakening Earth's defenses.
Homelander: Murdered Stillwell
For Homelander, the poster child for the Seven and a shining beacon for the world, his more evil deeds are those on a much larger scale.
When Billy Butcher of The Boys has the villainous Madelyn Stillwell, Homelander's love interest and boss held captive, Homelander, rather than trying to save her, proceeds to shoot his laser-vision right through her head, killing Stillwell in a brutal fashion. While it may not be the evilest thing he's done, it's definitely up there.
Omni-Man: Decimated Chicago
Contrasting Homelander, Omni-Man's more evil deeds are the ones that hit close to home, the ones that go against him being a father figure and loving friend. Omni-Man absolutely destroying Chicago stands as one of his more evil moments.
After being confronted by his son Mark AKA Invincible and telling him the truth, the pair end up battling across the world, with their fight spilling into the city of Chicago. Showing no mercy, Omni-Man tears through the city and lets countless civilians die brutal and undeserving deaths.
Homelander: Manipulated His Son
Similar to Omni-Man, Homelander does end up having a superpowered son, Ryan, with Butcher's wife Becca. Homelander starts off as a "caring" father but then by the end, tries to manipulate his own son with help from the equally scary Supe Stormfront.
With Stormfront's help, Homelander tries to turn Ryan against his mom and leave with him for Voight. While Ryan ends up with his true father figure, Billy Butcher, the manipulation from Homelander on a literal child is terrible beyond words.
Omni-Man: Destroyed An Entire Planet
Mass genocide is definitely a sign of a deranged and psychotic lunatic. Even before Chicago, Omni-Man was involved with his son in stopping an invasion by a race known as the Flaxans. In a bid to stop them, Omni-Man pushes their leader through their portal and onto their planet... where everything goes bottoms up.
Dropping the good guy routine immediately, Omni-Man uses the leader as a battering ram, reducing him to nothing before flying through the Flaxan homeworld so fast, it causes multiple nuclear explosions. In the end, Omni-man leaves the devastated planet although it's implied the race was making a comeback with plans to take revenge on the world-destroyer.
Homelander: Created Super Terrorists
Even good intentions end up being bad deeds. For the longest time, the world only knew of Superheroes. However, towards the end of season 1, super terrorists began to emerge, imbued with the same formula manufactured by Voight. Who gave it to them? Homelander.
In a bid to please Stillwell and get superheroes in the army, Homelander created the super terrorists to serve as a credible threat for the Supes to take on. In the end, Homelander's selfish actions led to the deaths of more innocents and the creation of superpowered anarchists.
Omni-Man: Slaughtered The Guardians
The first episode of any show is crucial in establishing the tone of the show. While most of Invincible was a typical superhero romp, the final moments of the episode changed everything.
Upon receiving a red alert, the Guardians of the Globe race to their home base only to encounter Omni-Man. Without saying a word, Omni-Man proceeds to brutally murder the Guardians one by one. In what's become only the tip of the brutal iceberg for the series, Omni-Man slaughtering the Guardians set the tone and precedent for the series.
Homelander: Abandoned The Plane
Homelander's done some pretty horrible things; he squished a man's head like it was a grape while having sex with Stormfront and framed the Boys for murder. Yet, him letting an entire plane full of people die was appalling.
It wasn't as brutal and vicious as some of his other actions but as a Superman archetype, Homelander is meant to be hope and a hero for the world. So just letting a whole plane of people die to better his own cause stands out among all the rest.
Omni-Man: Brutalized His Own Son
A big focal point for Invincible rests in the father-son dynamic and Mark growing into his father's shadow. However, when Mark learned who his father really was and refused to help him, all that love vanished as Omni-Man proceeded to beat his own son across the world.
From Chicago where he traumatized Mark with the murder of thousands to one of the most brutal beatdowns in a mountain, Omni-Man was dead-set on killing his son. While he showed a hint of emotion and regret before the killing blow, Omni-Man's actions still can't be discounted even if he may be heading towards redemption like in the comics.