- 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 becoming basically the complete opposite in every way. 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, and The Monarch was orphaned as a child and clawed his way into super villainy by his own merits.
- The Monarch has a somewhat tumultuous but long-standing and deeply romantic and intimate relationship with Dr. Girlfriend built on trust and respect, where Dr. Venture is a pitifully lonely bachelor and Casanova Wannabe.
- 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 Killinger suggested he would likely be much more dangerous as a 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 that 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.
- 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 seems inexperienced about how arching works.
Foil / The Venture Bros.