To Superman. As Kryptonians, they both have the same powers. The difference is that while Zod was specifically created to be a soldier (and thus uses authoritarian methods to build Krypton), Superman was naturally born and was able to gradually grow into the role of a protector.
To Jor-El. Both were aware that their homeworld was in danger from the hubris of the planet's leaders, but while Jor-El was willing to co-exist with other races, Zod only thought of conquering worlds.
In hindsight, Zod is one for the Martian Manhunter. Both are aliens who became generals and their duties put them at odds with Superman. The difference being that the Martian Manhunter always seeks out a peaceful solution while Zod's first instinct is to threaten and attack.
Lex Luthor in Batman v Superman: Dawn of Justice. Though he's Clark Kent's classic archenemy, Luthor serves as such to Bruce Wayne/Batman. Both have their classic traits of being wealthy businessmen who live something of a double life, but the binding element specifically to this film's story between them is how each reacts to the presence of Superman. Because of the ideal he represents and the power he possesses both are immediately distrustful and thus seek to destroy him. Both having lost their faith in the idea of absolute good after facing great personal struggles. Whether it be the the seeming futility of his years long crusade against crime in Batman's case which included at least one major loss with the death of a sidekick, or in Lex's the terrible abuse he was helpless to defend himself from by his father throughout his childhood. The existence of Superman only enhancing their senses of dread and helplessness. However Batman realizes the error in his ways when Superman becomes humanized in his eyes at the end of their battle when he uses his last words to try and make sure his mother is safe. Luthor on the other hand never manages to see him this way and in the process of trying to find a way to destroy him winds up creating the true monstrous and nearly unstoppable godbeast they thought Superman was in Doomsday. And ironically enough Superman winds up actually saving his life from the very monster he created.
Like Diana, Steppenwolf is a mighty noble armored warrior who wields a powerful bladed-weapon and comes from an ancient and powerful civilization. Both were forced to leave said civilization and centuries later they both express a homesick desire to return but are painfully aware that they can't. Unlike Wonder Woman however, Steppenwolf spends his life conquering life on other planets while Diana spends her life protecting innocent lives on Earth.
For Arthur both he and Steppenwolf are arrogant fighters (with a hidden softer side) who wield a two-handed spear to excellent effect. Both are estranged from their native lands and even argue with their allies over their respective banishments. Like with Diana though Arthur cares for others protecting and providing for them, unlike Steppenwolf who commits planetary genocide for the sake of being allowed to return to Apokolips one day.
In Aquaman, Orm is this to Arthur. Both are the sons of Queen Atlanna both are trained warriors who uses tridents as weapons and both blame someone for Atlanna's loss. The difference is that Arthur blames Atlantis and so rejects his birthright as King of Atlantis, whereas Orm is King of Atlantis and blames Arthur for his mother's death, since if she'd never had him she wouldn't have been executed for treason.
For Bloodsport both he and Peacemaker are a Crazy-Prepared, Walking ArmoryGun Nut who mercilessly kill whoever they required to as well as anyone who gets in their way. Except Bloodsport has a Hidden Heart of Gold who finds a Morality Pet in Cleo Cazo/Ratcatcher 2 and ultimately deicides to do the right thing and save Corto Maltese from Starro. Peacemaker on the other hand is a jingoistic Knight Templar who despite bonding with the squad, refuses to go against his government's wishes and is willingly to kill his own teammates to prevent the UN's secrets being revealed. Additionally Bloodsport is case of Dark Is Not Evil while Peacemaker is a case of Light Is Not Good.
For Rick Flag Peacemaker like him is a Badass Normal soldier working for Amanda Waller and are both extremely righteous and loyal to their causes. They diverge at the end when it's revealed the American government support the abhorrent human experiments using Starro. Rick Flag is utterly disgusted and refuses to cover up the horrors of his country and rightly betrays Waller. Peacemaker in contrast refuses to compromise his code even for basic morality and fights Flag over the evidence and kills him with Flag's final words expressing what a sick joke "Peacemaker" is. Rick's A Father to His Men qualities also contrast with Peacemaker's Team Killer actions.
He's even one to Superman. Much like Superman, Peacemaker is a muscular Primary-Color Champion that wears a symbol of benevolence on his chest. Both have also killed a military man that would turn on his own superiors out of principle and have been seriously injured by Bloodsport. A difference being that Superman only killed because he had no other choice, while Peacemaker killed Rick Flag despite having the option to either cripple him or destroy his leverage.
