One of the longest-lasting tropes in fiction is that of the protagonist's evil counterpart. Whether they're a twin, a clone or some other kind of copycat, audiences never seem to get tired of seeing heroes face off with someone on equal footing with them. It can also be a good way of developing a character, by putting them up against a dark reflection of themselves.

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Video games especially like to utilize this trope, resulting in a slew of evil twins, mechanical doppelgangers, and failed cloning experiments. More than just simple palette-swaps, many of these characters have gone on to become fan-favorites in their own right.

8 Copy X from Mega Man Zero

Copy X Artwork

After the original Mega Man X disappeared at the conclusion of the Elf Wars, a "perfect" duplicate of him was built to take his place as the ruler of Neo Arcadia. The result was Copy X, a Reploid with all of X's abilities but none of his experience. Under his rule, Neo Arcadia eventually became a dictatorship and led to mass executions of innocent Reploids.

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When the revived Zero finally met Copy X face-to-face, it was clear that he had a severe inferiority complex. Childish and egotistical, he demanded unconditional respect based on his predecessor's reputation, unwilling to accept that the original X's respect had been earned rather than simply given. His naivety proved to be his downfall at Mega Man Zero's conclusion.

7 Dark Samus from Metroid Prime

Dark Samus in Metroid Prime 3 Corruption

Created when the dying Metroid Prime absorbed Samus Aran's Phazon Suit, Dark Samus was a constant thorn in the bounty hunter's side throughout the Metroid Prime series. On top of sharing most of Samus' skills, it had plenty of its own due to its power over the highly deadly substance Phazon.

Dark Samus proved to be a nearly unkillable adversary, even reconstituting itself at the end of Metroid Prime 2: Echoes after a Phazon overload caused it to disintegrate. It took Samus completely destroying the source of all Phazon in Metroid Prime 3: Corruption to defeat her doppelganger permanently.

6 Noob Saibot from Mortal Kombat

Noob Saibot in Mortal Kombat 11

While the Sub-Zero most are familiar with is a largely heroic figure, the same can't be said for his older brother Bi-Han, aka Noob Saibot. The Sub-Zero who appeared in the first Mortal Kombat game, he was killed by a resurrected Scorpion after previously murdering him in cold blood.

Bi-Han returned as a wraith known as Noob Saibot, with what little good that was left in his soul stripped away. Now a being of pure darkness, he seeks to conquer the Netherrealm for himself, even if it means working with his brother's enemies to do it.

5 Metal Sonic from Sonic the Hedgehog

Metal Sonic & Sonic on Sonic CD Vinyl Cover

Sonic has had plenty of foes over the years that have since put their differences with him aside, such as Knuckles and Shadow. One rivalry that still burns hot is the one between him and Metal Sonic, Dr. Eggman's most successful attempt at duplicating Sonic's speed and power. With his sleek and menacing design, he's one of the most recognizable adversaries from the Sonic the Hedgehog series.

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Designed with the sole purpose of surpassing his template, Metal Sonic's single-minded pursuit of this task has led him to occasionally betray his own creator, as well as perform modifications on his own body to increase his efficiency. His obsession even causes him to sometimes call himself the "true" Sonic the Hedgehog.

4 Vergil from Devil May Cry

Vergil in Devil May Cry 5

Son of the Dark Knight Sparda, Vergil is the Yin to his brother Dante's Yang. While Dante is free-spirited and in touch with his human side, Vergil has a much colder demeanor and fully embraces his demonic lineage, along with the power that brings. In his own words: "Might controls everything - and without strength, you cannot protect anything; let alone yourself."

Despite being the antagonist of the Devil May Cry series, Vergil does have a few somewhat redeeming qualities that his more heroic brother lacks. Dante has no qualms about breaking the rules and fighting on his own terms, as long as it gets the job done. Meanwhile, Vergil has a strict code of honor, refusing to use firearms or use underhanded tricks against worthy opponents.

3 Akuma from Street Fighter

Akuma in Teppen

As Ryu pushed himself to become a stronger fighter, he was always at risk of falling to the dark side of the Satsui no Hado. Akuma, the brother of his master Gouken, represents the power he could wield, as well as the type of person he would become if he did. Like Ryu, he is always searching for worthy opponents, but when he fights it is almost always to the death.

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While acting like a devil on Ryu's shoulder, tempting him to follow the same path he did, Akuma still holds onto his own personal morals: he does not perform wanton violence and refuses to fight or kill those he considers beneath him. At worst, he could be considered of lawful evil alignment, compared to a more neutral evil antagonist like Bison.

2 Liquid Snake from Metal Gear Solid

Solid Snake & Liquid Art by Yoji Shinkawa

One of the products of the "Les Enfants Terribles" project, which aimed to create clones of the legendary warrior Big Boss, Liquid Snake received his father's dominant genes while Solid Snake was left with the inferior ones. This fact was kept secret from him, leading him to falsely believe that he was the genetically inferior of the two.

He died at the end of Metal Gear Solid, but not without making a big impact on fans, no doubt helped by the over-the-top vocal performance from Cam Clarke. Hideo Kojima himself admitted that, had he known how positive the reaction towards Liquid would have been, he would not have killed him off so quickly.

1 Wario from Super Mario

Wario in Wario Land Shake It Artwork

Described as a childhood acquaintance of Mario who was always envious of his popularity, Wario made his debut in Super Mario Land 2: 6 Golden Coins for the Game Boy. Initially just another in a long string of Mario antagonists, Wario struck a chord with fans that other attempts like Tatanga and Wart didn't. He continues to make appearances within the Super Mario franchise to this day.

Wario has done something that few evil counterparts in gaming have managed: become a breakout character in his own right. With the Wario Land and WarioWare franchises, he's been able to establish his own mythos separate from that of his rival. In a way, he's actually achieved his goal of escaping from Mario's shadow.

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