Hank and Dean Venture are an interesting example - they started out with identical personalities (parodies of eager Hardy Boys-type characters who were forever looking for mysteries to solve while having little to no real world experience), before growing into complete opposites over the course of the series. Where Dean is sensitive, Hank is masculine; where Dean is shy and afraid of girls (thus failing to win their affections), Hank is overeager and thinks of himself as a ladies man (while failing to win their affections); and most importantly, where Dean just wants to be normal, Hank just wants to be badass.
The Monarch to his nemesis Rusty Venture, in a number of ways:
Rusty and The Monarch both inherited hefty fortunes from their departed parents, but Rusty lost his father in his adulthood and cruises through the "super-science" world on the coattails of others' successes, while the Monarch was orphaned as a child and clawed his way into super villainy by his own merits, not even gaining access to his trust fund until he had already established himself as a villain.
The Monarch's hatred for Dr. Venture is almost tragically one-sided, to the point that he's usually considered a persistent nuisance at worst. This is largely thanks to their difference in manpower, with The Monarch's utterly inept legions of devoted henchmen falling in almost comical droves before Dr. Venture's single bodyguard.
Dr. Venture is a rather apathetic man in matters where his own ego and wealth aren't concerned, including The Monarch's one-sided obsession with ruining his life, and is riddled with self-doubt and unresolved trauma. The Monarch is defined by his almost inspiring passion for hatred and villainy, and has so much confidence in his abilities and purpose that his countless failures, his wife's pleas, Brock's wrath, and even strict Guild restrictions cannot dissuade him from pursuing his goal.
Doctor Venture is a Failure Hero, and Dr. Killinger tries to turn him into an outright villain. The Monarch is an Ineffectual Sympathetic Villain who proves frighteningly effective whenever he assumes the mantle of heroism. This even goes in line with their fathers; both had heroic fathers, but Rusty is universally agreed to be a disgrace to his father's legacy, while the Monarch had criminals fearing the return of the Blue Morpho after just his first night out.
Dr. Orpheus to Rusty Venture, in numerous ways:
In many respects, he is the opposite of Rusty—even aside from the obvious Magic Versus Science angle. Rusty is notoriously lazy and coasts on his inheritance and childhood fame and fortune, while Orpheus is a workaholic who earned his powers through great study and practice. Rusty is a notoriously jaded and cynical Deadpan Snarker, while Orpheus is a dramatic Large Ham who treats even the smallest actions as a big deal. Rusty is self-centered to the extreme and rarely does anything without a profit motive, while Orpheus is incredibly moral and describes himself as a protector of the mortal realm. Rusty hates being involved in the nonsense of the Guild and the Monarch, while Orpheus actively sought out an archvillain and takes genuine pleasure in his adventures.
He contrasts Rusty's terrible parenting by being a good father to Triana. His intro episode shows him recording a message just to let her know he's popped over to the other side of the compound for a bit, but she can have one of the puddings in the fridge. He's very involved, but not smothering. Meanwhile, Rusty causes the boys to get into trouble by angrily shooing them away every time he sees them, and has socially crippled them to the point that Dean's attempts to talk to Triana are incredibly pathetic even by teen-boy-with-a-crush standards. However, it's later revealed that his workaholism tends to get in the way despite his good intentions.
He's also the opposite in terms of how he treats his child's future. Rusty drags Hank and Dean into his job, and repeatedly ignores their resistance to him or treats it as unimportant. Orpheus does everything he can (even wiping her mind of meetings with the Master) to ensure that Triana won't be following his path, because he's abundantly aware of the terrors of it. And unlike Rusty, once he's had complete confirmation of what the best path for her is, he avidly supports it.
Warriana is one to Molotov Cocktease. Both are strong, independent women who are incredible fighters, absolutely deadly to mess with, and have a romantic relationship with Brock Sampson. However, they differ in many ways. Molotov is a mercenary/secret agent that works covertly and does her job for a paycheck. Alexis has a normal job in the limelight where thousands of people see her every day and the same goes for her Warriana guise that she uses to help people because Good Feels Good. Molotov is slim, agile, and tricky in a fight while making up for her lack of brawn by fighting dirty and using any weapon she can get her hands on. Alexis is a Statuesque Stunner and an Amazonian Beauty with Super-Strength who only relies on a few weapons and primarily uses her fists while having a straightforward fighting style. Molotov is The Tease with Brock and often manipulates him using guile and her feminine wiles to get him to do what she wants and while she often gets into combat with Brock has never truly gotten close to him as she only cares about Brock the secret agent, not Brock Sampson the loyal bodyguard and member of the Venture family and they have never consummated their relationship. Alexis and Brock clash initially as serious Belligerent Sexual Tension while arguing and mocking each other. Yet later, Alexis respects Brock as a man and doesn't mind meeting him on or off the job and seems to prefer Brock the man to Brock the secret agent. Unlike Molotov, Brock chased her and shared his honest feeling with her which resulted in a lot of sex.
Professor Victor Von Helping and Red Death. Both of them are very affable outside of their job and care a lot for their family and students, even going berserk and terrifying anyone who puts their loved ones in danger. They also lack a true face and can vaporize people with their powers, though Victor uses fake skin to hide his body. However, Red Death enjoys the supervillain life and relishes in killing people whereas Victor loves to help people and rebelled against the "supervillain" life as the son of legendary Guild villain Victor Von Hellfire.
Dr. Killinger to the Investors. While the Investors are fully villainous individuals who make Deal with the Devil-type deals with their clients and exact steep payments (up to their very lives) in return, Killinger is an Anti-Villain who acts as a Trickster Mentor who helps his clients to understand what they actually want/need, then assists them in earning it, instigating Character Development. Made all the more apparent in "All This and Gargantua-2" where they are revealed to be from the same class of Ambiguously Human beings and implies they may all four be brothers. Killinger chastises the other three, stating that they are all here to help people, but that the others lost their way.
Brock and Red Death. Each is quite possibly the deadliest member of their given organizations (O.S.I. and Guild, respectively) but each has spent much of their career in a role below their abilities (Brock because he was demoted to play Rusty's babysitter after getting too close to the Guild and Red Death because he has separated his professional and personal lives to such a degree that the latter is impacting his ability to do the former). They both share an intense bloodlust (Brock in more of a Blood Knight sense while Red Death is more Ax-Crazy when he has his Game Face on) that they've each learned to control (Brock via Character Development as seen in episodes like "Viva los Muertos!" while Red Death uses his villain career as an outlet to keep it separate from his family life) while both are, deep down, Nice Guys (Brock in a Papa Wolf, Jerk with a Heart of Gold way and Red Death as an Affably Evilfamily man).
