There are times in a story where a character on one end of the alignment of whatever ethos they follow is a Challenge Seeker. Longing for someone who they can match wits and strength with as a Worthy Opponent. Not competition, but someone who makes the character define who they are in the world since they are often Desperately Looking for a Purpose in Life. An opposite. A negative. A Yin that completes their Yang. Someone to balance them out and give them a reason to get out of bed in the morning. Even more so if it turns out a character has all they need in life and just want some excitement in their lives.
That is when this trope comes in. Opposites Attract on a conscious level.
This trope is when a character is marked by their stated desire to find an entity deemed as their opposite or nemesis in order to fulfill whatever desire they have in life. Often done by a Big Bad of some story in the form of Create Your Own Hero so they can have someone to do battle with. Other times even done by a Big Good to Create Your Own Villain because Good Needs Evil so they can have someone to express their idea of heroism against. After all, Enemies Equals Greatness, and this character wants their perfect enemy to boost themselves to new heights of importance. On a general level it can be done by any being harping on about the Balance of Good and Evil and how one side must be counterbalanced by parties of another to feel whole or to fulfill some setting significance.
If the opposing parties can act on friendly terms despite their differences, compare Go-Karting with Bowser, where the nemeses spend time as friends when they aren't killing each other. If the character outlives their nemesis, always expect them to be an Antagonist in Mourning just praying for a suitable replacement if possible.
Due to the nature of the trope, there will be unmarked spoilers in abundance. You have been warned.
- This ends up happening to Light Yagami in the second half of Death Note. Light ultimately manages to best L, kill him and can create his perfect world uncontested while leading the Kira Task Force around in circles. But after four years, he finds himself growing bored and actually longing for an enforcer of law to match wits with again. When L's successors, Near and Mello, come to challenge him, he's actually elated to finally have someone coming after him again and eggs them on to try and catch him.
- In One-Punch Man, the eponymous Invincible Hero Saitama has trained hard so he can enjoy the thrill of the fight against villains, but ended up too powerful in that he ends fights in, well, one punch. While he's not above general heroics and helping innocents, his main drive is to find a villain opponent on his level.
- The entire plot of Oxymoron is kicked off by the title Villain Protagonist going on a bloody crusade against contradiction and hypocritical people as part of his Black and White Insanity and personal status as a Card-Carrying Villain. As mentioned in the page quote, he's also searching for an ultimate example of good to counteract his evil and serve as a worthy opponent to suite for his own twisted idea of "greatness" and puts two of his cop victims through Hell to see if they will become his nemesis. He's a Joker without a Batman.
- In A Shadow of the Titans, Beast Boy is thrilled when Jade declares him as her Arch-Enemy after he particularly angers her, as he feels that this makes him cooler. An exasperated Cyborg tries very hard to get it through his head that he shouldn't be happy that there's someone out there who hates him that much.
- Played Straight and Lampshaded in Megamind where Megamind seemingly destroys his superhero archenemy Metro Man and falls into depression soon after taking over the city. He eventually realizes being a villain is not worthwhile without a hero to stop him and tries to groom a new person to become a hero worthy of him, with disastrous results.
Megamind: Minion, I'm a villain without a hero. A Yin with no Yang. A bullfighter with no bull to fight. In other words, I have no purpose!
- In Bram Stoker's Dracula, Professor Van Helsing is ecstatic when he deduces the Count's identity and realizes he is a powerful immortal vampire, calling him "the enemy I have waited for all my life."
- Agent Smith is The Matrix Revolutions mentioned to be wanting this according to the Oracle when Neo asked him what he became after Neo defeated him in the past. According to the Oracle, Smith has become as antithetical to the program of the One as possible and seeks to search out and destroy the One to finally take hold of the Matrix and the real world and destroy everything.
Neo: What is [Smith]?
Oracle: He is you. Your opposite, your negative. The result of the equation trying to balance itself out.
- Mystery Men gets kicked off when the superhero, Captain Amazing, is too good at his job, and doesn't have a Cardboard Prison for his nemeses. By the start of the movie, all of the villains he'd detained over the years have either been executed or been committed. Desperate, he arranges for a former nemesis, Casanova Frankenstein, to be released from an insane asylum to maintain his job. It ends up backfiring when Casanova captures him, prompting the protagonists of the story to step up and stop Casanova.
- Mr. Glass of Unbreakable was revealed to be the Big Bad behind a series of horrible disasters with massive casualties because he wanted to find and groom a heroic figure who would be his opposite in morals and body that would counteract his Evil Cripple status. His own superhero to give his life meaning as a supervillain.
- In Captain Freedom, the titular superhero spends much of the book searching for a supervillain who will embody his own personal demons so that he can beat them up and feel better about himself. In the end, he finally meets his supervillain - his old school nemesis Scoop.
- In Disgaea 3: Absence of Justice, Super Hero Aurum came to Evil Academy to battle the Strongest Overlord, Mao's father, but after effortlessly defeating the Overlord (whom was holding back to keep from injuring Mao with an attack), he laments that he might as well fade into obscurity completely unfulfilled. Mao attacking him out of the blue for breaking his promise to merely beat up the Overlord planted the idea for Aurum to turn Mao into his new great adversary. If one couldn't be found, then he would make his own.
- Harley Quinn features this issue in the episode "Finding Mr. Right" where Harley desperately wants a nemesis so people will take her seriously as a villain. The whole "nemesis" thing is treated as romantic relationships and/or sex, complete with a "dating" site for finding compatibility. Harley eventually becomes stuck with Robin the Boy Wonder as her nemesis, which she is not happy about, and attempts to either get rid of him or trade up. Once Robin stops being Harley's nemesis, he complains about wanting one because all his fellow Teen Titans have one, prompting Batman (his father) to tell him how he will find one when he is ready.
- Stated outright in The Venture Bros.. Evidently the villains like the "arch" (as in -enemy) system, in which each is matched with a nemesis. Break up the system and you're just going to have a bunch of pissed-off guys with death rays, and that wouldn't be good for anyone. Best demonstrated when the Monarch lost Dr. Venture as his nemesis and started killing new designated arches in droves because they were not worthy of his hatred like Dr. Venture.
- Some of the good guys like it too. Heavily featured in the episode "Tag Sale, You're It!" where Dr Orpheus tries to attract an archnemesis for the romance, drama, and attention of it all, to the point of antagonizing some villains and then offering them his business card. (And Pete White mentions wishing he and Billy had Dr Girlfriend as their archnemesis just cuz she's hot.)
- Explored a little in Justice League Unlimited where Shadow Thief is portrayed as the Enemy Without of Hawkman's nature. Carter Hall wanted to be a hero, so his darker impulses of his subconscious manifested as a villain and nemesis for him to fight. The moment Shadow Thief revealed this, Carter destroyed him.
- In the first season of Frisky Dingo, Xander Crews devotes much of his efforts to creating and/or cultivating supervillains in order to justify wasting his company's money maintaining his superhero alter-ego Awesome X. This ends up backfiring in season 2 when actual supervillain Sinn turns his engineered supervillains Dread Lobster and Antagone into an actual threat, ultimately resulting in a giant hideous ant-human hybrid rampaging through The Town.
- Displayed in The Simpsons in the episode "Sweet Seymour Skinner's Baaaadaaaaassss Song", where Bart accidentally gets Skinner fired from his position as a principal and they become more friendly to each other now that Skinner is a private citizen. Soon enough Bart feels that something isn't right and tells Lisa. Lisa puts it as Bart yearning for a disciplinarian nemesis, someone he can rebel against (and in the meanwhile Ned Flanders has been placed as the new principal, who is so driven to be friendly that he does nothing to enforce order and allows the school turn into a hellhole). With this in mind, Bart decides to help Skinner regain his job.
- In Phineas and Ferb, Doctor Doofenschmirtz and Perry the Platypus are defined by their mutual animosity for each other. In "It's About Time!", Doofenschmirtz decides to shake it up a bit by fighting Peter the Panda instead, which leaves Perry in a depressed funk. Soon afterward, Doofenschmirtz is also feeling the blues after Peter fails to respect their hero-villain dynamic, joyfully reminiscing about how he first met Perry in the song, "My Nemesis".
I used to sit alone doin' evil all day,
But now I think there's someone gonna get in my way,
There's someone in my life that don't want me to exist,
(My neme, neme, oooo... my neme, neme, neme)
And I feel fine cause I've got a nemesis!
- The Ever After High character Apple, who was molded by society to become a perfect archetypal princess, becomes upset when the girl designated as the Evil Sorceress in their narrative rebels. This is partly because of Apple's obsession with order, and partly because when the patterns of that world are disrupted, bad things happen.
Maddie: Like all fairytale princesses, she needs an archenemy to be the yin to her yang and make her feel ~complete~."