Become Their Own Antithesis

Characters, most characters, change over time. Be it Character Development, a Heel Face Turn, or even Flanderization, characters rarely end a work the same as they began it.

Some characters however have somehow managed to take a good long look at everything they were at the start and become a perfect photo negative of it.

More often than not, this trope is used to emphasize just how far a Fallen Hero has fallen; though it rarely prompts a My God, What Have I Done? moment; but can also be used to show how much of a positive impact that good has had on a person.

Note that this trope, through the use of a Morality Dial, can be invoked artificially.

Compare He Who Fights Monsters.

Examples of Become Their Own Antithesis include:

Anime and Manga

• Remember Tobi from Naruto? You might know him as Obito.

Comic Books

• Doctor Who (Titan):
  • Four Doctors features three Alternate Universes where the Tenth, Eleventh, and Twelfth each fall victim to this. The Tenth went full Time Lord Victorious and conquered the universe, the Eleventh allowed reality to remain locked at April 22, 2011, and the Twelfth became a crazy hermit. When faced with the Big Bad, the alternate Twelfth Doctor, Twelve all but quotes this.
  • In Supremacy of the Cybermen, Twelve notes that, by allying with the Cybermen and using their cybernetic upgrades, Rassilon has spat in the face of the "Time Lord purity" he's sprouted his whole life.
• For years, General Ross hunted down the Incredible Hulk, branding him as a great threat to Earth's safety. Then Ross turned himself into the Red Hulk, being pursued by the US military and being labelled as a deadly threat, just as he'd done to Banner.

Fan Works

• In Canon Fodder, Salvage notes that, due to a variety of socio-political factors, the Autobots and Decepticons have essentially switched causes over the course of their Forever War.
• In Chapter 21 of Enough Rope, Steve Rogers, upon learning that the Chitauri are on their way back to Earth, decides to turn himself in to the United Nations, noting to Sam Wilson that by signing the Sokovia Accords, they can use their political influence to champion for changes from within the system. As Sam incredulously points out, this is exactly what Tony suggested they do from the start, and the very same idea that Steve championed so passionately against.
• Freddie Benson in OneHorseShay's iCarly/Victorious crossover series. Truly an impressive accomplishment as this version of Freddie is an out Out of Character In Name Only OC Stand In who somehow managed to stand for everything he said he opposed. In the first story, iActually Like Mean Girls, he violently calls Carly out for always standing by whenever Sam is physically and emotionally cruel to others and dismantling Carly's argument that everyone else needs to "understand" Sam or take her Freudian Excuse into account when Sam is clearly doing everything For the Evulz. By the next story, Freddie would be doing absolutely nothing whenever Jade was cruel to someone, outright telling Tori that people had to consider Jade's Freudian Excuse and "understand" Jade before judging her, and had begun physically attacking people that he didn't like.

Films

• Star Wars:
  • The whole Prequel Trilogy is Anakin going from idealistic and adventurous Jedi to restrained Sith Lord. Obi-Wan lampshades this just before their duel in Revenge of the Sith.
  • When the Galactic Civil War broke out, the Empire branded the Rebels as terrorists who cling to the old style of government. Guess what sentiment best describes the First Order, the Empire's successor state, in The Force Awakens.
  • The Rise of Skywalker sees Luke and Rey reverse their stances from The Last Jedi with regards to a powerful Jedi banishing themselves to Ahch-To. They even hang a lampshade on it.
• Optimus Prime in Transformers: Age of Extinction. From the Autobot most resistant to the idea of harming humans to the one who swears to kill whatever Corrupt Politician is funding the CIA hunting down the Cybertronians on Earth.

Live-Action TV

• Doctor Who:
  • The Tenth Doctor's moment as the Time Lord Victorious. If you saw that clip out of context, you'd be forgiven for thinking that Tennant was playing the Master.
  • The Twelfth Doctor totally outdoes him after Clara is killed. So much does Twelve grieve for his lost love that he's willing to fracture time itself to get her back.
  • Several characters; from Davros to River Song to the Doctor themselves; have discussed this about the Doctor. Davros notes that the Doctor, despite being heralded as a champion of justice, is soaked in a lot of blood, River notes that the Doctor has now become a Living Legend instead of just a simple "Cosmic Hobo", and the Doctor has noted that the First Doctor was actually kind of a dick instead of the more overtly heroic person that their later incarnations have grown into.
  • The Cybermen in the Series 12 finale. They started out as Well-Intentioned Extremists who wanted to help organics survive by becoming cyborgs. In "The Timeless Children", they've devolved into Killer Robots who indiscriminately kill organics.
• Archie Andrews in the second season of Riverdale, thanks to the influence of Hiram Lodge. Thankfully he realizes this in the season's penultimate episode.
• Red Kryptonite has this effect on Kryptonians in both Smallville and Supergirl.
• In the Star Trek: The Next Generation episode, "The Wounded", Captain Ben Maxwell accuses Picard of becoming just like the Starfleet's Good Is Impotent/Obstructive Bureaucrat core of admirals that the captains try to avoid becoming like. Though Picard's attitude seems to support Maxwell's belief throughout the episode, the ending subverts it by revealing that he fully agrees with Maxwell's motives, if not his actions, regarding the Cardassians. Picard was simply ordered to protect a hard earned peace.

Western Animation

• Rick C-137 accuses the Council of Ricks of this in Rick and Morty. They wanted to escape the government so they became a government all on their own. Candidate/Evil Morty reiterates this belief in Tales From the Citadel, noting that every Rick who fled to the Citadel of Ricks has had to become a working class man, never being allowed to use their genius.
• The usual backstory for Transformers is that the lineage of the Primes, after billions of Earth years of undisputed rule, have become decadent hedonists. The one who rose up to tear down their system, Megatron, ultimately ended up becoming just as corrupt as the Primes themselves.
• Voltron: Legendary Defender:
  • Zarkon was once the Black Paladin but is now Emperor of the Galra Empire and practitioner of the very atrocities that he once led Voltron to fight against. In his defence, he is Drunk on the Dark Side.
  • The Altean Empire in Hole in the Sky. Altea was a culture of artisans and healers who abhorred violence and it's now The Empire.