Nega-Scott of Scott Pilgrim. In the true Jungian tradition, Nega-Scott represents everything about himself that Scott doesn't want to deal with, both his flaws, his mistakes and his true potential as a better person. However, what worsens and complicates matters is that Gideon tampered with Scott's memories, thus making Nega-Scott's nature even more dubious. In fact, given its appearance when Scott began going out with Ramona and the mechanics of The Glow (the psychological weapon Gideon made that traps you in your own head and brings out your worse tendencies), it's possible that Nega-Scott didn't truly exist until Gideon messed with Scott's mind in the first place. In a potential case of Wrong Genre Savvy, Scott finally clashes with his shadow and believes if he defeats Nega-Scott, he can move on. However, the battle ends when Kim explains what it actually means and Scott absorbs Nega-Scott.
Sonic the Hedgehog (Archie Comics): Anti-Sonic/Scourge, Sonic's Evil Twin/Mirror Universecounterpart, is Sonic with all of his negative qualities ramped up, and very few, if any, of his positive ones, and is living, breathing proof of what our hero would become if he went down a dark path. Scourge is fully aware of this, and gloats in issue 172 that this is why Sonic hates him so much, remarking that all it would take is "one bad day" to make Sonic just like him. Come issue 236, Sonic, after suffering through Sally's roboticization, Antoine's near-fatal Heroic Sacrifice saving Elias' family, and Silver's Inspector Javert tendencies at the worst possible time, is pushed to his Rage Breaking Point, and only by recalling Scourge's prior "one bad day" speech does he manage to pull himself back.
Surge the Tenrec and Kitsunami the Fennec, a pair of cyborgs created by Dr. Starline to serve as replacements for Sonic and Tails, respectively, in his plan to take over the world by manipulating the "hero-versus-villain" dynamic, intentionally created to replicate their abilities and personality attributes. Unfortunately, the realization that they were manufactured by Dr. Starline, combined with the effects of Starline's brainwashing wearing off, causes them to go out of control and embody some of the worst qualities of their progenitors. Surge shares Sonic's free-spirited nature and confidence, but she is also extremely violent and revels in sowing chaos and destruction, and whereas Sonic loves to playfully tease his opponents, Surge is viscous in her taunts and more than happy to Break Them by Talking. Meanwhile, Kitsunami is fiercely loyal to Surge, much like Tails is to Sonic. However, where Sonic considers Tails his friend and equal, Surge considers Kitsunami her subordinate — a belief that also extends to Kitsunami, who is an Extreme Doormat, his mind hard-wired to acquiesce to Surge's wants and desires, even at his own peril.
Dr. Starline, himself, serves as a sharp contrast to Dr. Eggman, whom he initially idolizes and aims to emulate. During their short-lived partnership, however, Dr. Starline begins to see flaws in Eggman's methodology, from his fickleness regarding past plots — regardless of how close to successful they may have been — to his single-minded desire to best Sonic. Dr. Starline, meanwhile, establishes Eggman as A Lighter Shade of Black early on when he shows that he has no compunctions with killing Sonic and his allies, something that draws Eggman's ire: Eggman doesn't want to kill Sonic, just beat him and prove himself superior, which he can't do if his nemesis is dead! Dr. Starline eventually branches off on his own to try and conquer the world himself, showing himself to be far more subtle and cunning than the bombastic Eggman, but also more willing to delve into dark and morally objectionable methods to accompish his goals, including brainwashing, torture, and live experimentation. In time and by the end of his life, he becomes Hated by All, reviled by heroes and villains alike — Even Dr. Eggman sees him as reprehensible beyond all measure!
Star Wars: Doctor Aphra: Aphra realizes during the Star Wars: The Screaming Citadel, Aphra eventually realizes that this is the case for her and Luke. Both grew up on backwater Outer Rim worlds, and lost loved ones to random acts of violence, but whereas Aphra became The Cynic who sees only the bad in the universe, Luke has managed to maintain his optimism and hopefulness. Aphra is shown to be quite disconcerted by this epiphany.
Star Wars: Han Solo - Imperial Cadet: Yurib Nakan is essentially what the older Han Solo would have been like had he remained a loyal Imperial officer.
Nakan: I came from chaos, Solo. Just like you. I eventually became the best for one reason and one reason only: I followed orders. The Empire is order, Solo. The end of chaos.
Megatron is eventually set up to be the shadow to Optimus Prime. Before the War, both were young, idealistic, and wanted to make Cybertron a better place; indeed, there was a degree of mutual respect whenever they crossed paths. However, Megatron gradually abandoned his ideals in the fires of the war, becoming a bloody-handed tyrant no better than the corrupt Senate or the Functionist Council, while Optimus fought to retain his basic optimism. When a penitent Megatron had another chance after travelling to the Functionist universe, he basically became the Optimus Prime figure to that universe's Optimus Prime.
Getaway to Rodimus. They have a very similar list of faults, save one: while both are manipulative and ambitious, Rodimus at least tries to temper it with loyalty to his crew and finds people who will call him out on his actions, while Getaway views everyone else as a pawn and Can't Take Criticism. Best exemplified when one comic has them both make cracks about how Perceptor > physics, but Getaway then feels the need to put down Highbrow for not getting his oh-so-funny joke.
Across MTMTE and The Transformers: Robots in Disguise, Tarn of the Decepticon Justice Division ends up as this to Soundwave. Both are Decepticon partisans with themed teams of allies who remain devoted to the cause after the war ends (they even look similar; Soundwave's design was the out-of-universe inspiration for the Decepticon insignia in the early days of the franchise, and Tarn literally wears the Decepticon symbol as a face mask). However, Soundwave has lines he won't cross, a genuine faith in the Decepticon cause and a true bond with most of his allies, while Tarn turns out to be obsessed with Megatron specifically and ends up abandoning his few remaining morals and killing one of his fellow DJD members in pursuit of revenge against Megatron for doing a Heel–Face Turn. Tarn's powers are based on speaking, and he mostly uses them to kill; Soundwave's are based on listening, and it helps him recognise a kinship between humans and Cybertronians and start to value organic life as well. Even their deaths end up diametrically opposed: Soundwave makes a Heroic Sacrifice against Unicron and dies united with the living and the dead, finding some measure of absolution for his deeds, while Tarn dies alone, consumed by hatred and antimatter, being told that at the last all his atrocities were for nothing.
In Avatar: The Last Airbender – Imbalance, it's easy to see Ya Ling and Ru Ling as Katara and Sokka respectively if the two water nation siblings allowed Katara's bending to drive a rift between them.
In The Stuff of Legend, The General is one to the Colonel, as both are military-type toys that have each spent time as the Boy's favorite. But while the Colonel has Undying Loyalty to the boy, the General was corrupted by the Boogeyman.
Disney Ducks Comic Universe: Like Scrooge McDuck, Flintheart Glomgold is a cheap old miser who lives in a bin full of money, except in South Africa. However, Glomgold'swhole character is essentially a Scrooge who never made his fortune square, not to mention his lack of friends in comparison to Scrooge's large group of family. Also, Glomgold will use underhanded means such as deception and murder to become wealthier than Scrooge if he thinks he can get away with it.
In Gravity Falls: Lost Legends, Anti-Mabel herself says that every selfish choice Mabel makes, that’s her being Anti-Mabel.
Usagi Yojimbo has Jei to Usagi. Both are highly-skilled ronin who are dedicated towards defeating the forces of evil, but the main difference is that while Usagi earnestly wants to protect the innocent, Jei mercilessly hunts down anyone he deems a sinner.
