While Sonic the Hedgehog’s reputation as a franchise ebbs and flows with the passing of generations, it’s hard to imagine a world where the blue blur isn’t inherently ingrained into the video game medium. This is a character who was once Sonic’s de facto rival as far as the industry is concerned. Things have changed considerably since, but Sonic persists as best he can. 

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Like any franchise that goes on long enough, Sonic has evolved with time, introducing new characters and story beats to fill out its world. Of the cast, Sonic’s rivals stand out as some of the most engaging characters in the franchise, with Metal Sonic & Shadow arguably his biggest of the bunch.  

10 Metal Sonic: Nature Versus Technology

The franchise’s nature versus technology themes are not unique to either Metal Sonic or Sonic CD, instead being rooted in Sonic the Hedgehog’s very identity. Dr. Eggman’s entire motivation is based on a perversion of nature– entrapping animals and using them as living fuel for his robots while also destroying the environment. 

Metal Sonic carries this idea to its logical conclusion in Sonic CD, representing Eggman at his most competent. Not only has the doctor managed to create a near perfect replica of his archenemy, CD is the game where Eggman arguably does the most damage– damaging the environment to extreme scales with Metal Sonic’s help. 

9 Shadow: Nature Versus Nurture

Now, the theme of nature versus nurture doesn’t really apply to the rivalry between Sonic and Shadow, but it’s an integral part of Shadow’s character which ultimately makes him a good rival for Sonic when push comes to shove. Throughout Sonic Adventure 2, Shadow is essentially operating on the behalf that because he is the Ultimate Lifeform (paired with his distrust of humans,) it’s up to him to wipe humanity out. 

Over the course of the game, however, Shadow’s nature (being the Ultimate Lifeform) is challenged by his resurfacing memories of Maria, each one revealing the values she instilled in him (nurturing his true personality & allowing him to naturally enter the main cast.) 

8 Metal Sonic: Sonic’s Natural Foil

When looking ast Metal Sonic and Shadow side by side, it’s hard not to see the former as Sonic’s clear, natural foil. Taking Metal Sonic just on a surface level, his design is lifted straight from Sonic’s– both in and out of universe. He was built with the sole purpose of combating Sonic by being a better Sonic than Sonic. 

As Metal Sonic spends most of his debut game, Sonic CD, terrorizing Amy and trying to instill a dystopian future on Eggman’s behalf, Metal Sonic feels right at home as yet another villain for Sonic. Better yet, his boss fight capitalizes on the series’ trademark speed better than most bosses in the Genesis trilogy. 

7 Shadow: Sonic’s Thematic Foil

Where Metal Sonic is Sonic’s natural, logical foil when you take into consideration the franchise and character’s core values, Shadow offers a more thematic foil for Sonic. The two rarely narratively coalesce, but that in itself is important as it allows Sonic and Shadow to grow independently as characters alongside each other. 

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They rarely interact in SA2, but their actions and motivations contrast each other nicely. The same for Sonic Heroes where Sonic serves as his team’s natural leader with Shadow needing to take a backseat. Beyond roles, Shadow brings a subdued cool that pairs well with Sonic’s in your face attitude. 

6 Metal Sonic: Twists Sonic’s Iconography 

Sonic the Hedgehog is basically character design boiled down to a science. He is scientifically cool, a character who came into existence for mostly commercial purposes. All the same, Sonic quickly adopted an identity of his own– a nature loving hedgehog with a penchant for adventure. This contrasts nicely with Metal Sonic’s dark, sleeker design. 

Unlike Sonic who’s always been incredibly expressive for a platforming mascot (his idle animations blow Mario’s out of the water,) Metal Sonic can’t emote at all. He’s cold, calculating, and devoid of Sonic’s warmth while also twisting the hedgehog's familiar image in the process. It makes for some strong character design. 

5 Shadow: Identity Independent Of Sonic

As appreciable on a design level as it is that Metal Sonic takes Sonic’s iconic imagery and twists it completely, it does result in his character being intimately tied to Sonic. How can it not when his name is “Metal Sonic?” Even in Sonic Heroes where Metal Sonic is given dialogue, there’s very little to actually unearth under the surface. 

Which isn’t the case whatsoever with Shadow. Even though he’s introduced as a dark Sonic who characters keep mistaking for the real Sonic, Shadow has a very defined personality and backstory that have absolutely nothing to do with the blue hedgehog. Even his arc in SA2 runs independent of Sonic’s for the majority of the game. 

4 Metal Sonic: Sonic’s First Real Rival

Although Shadow may be Sonic’s latest rival (more on that in just a bit,) it’s important to respect the original. Introduced in 1993’s Sonic CD for the Sega CD, Metal Sonic became Sonic’s first true rival. Designed by Dr. Eggman to combat Sonic in every way imaginable, he’s– as mentioned– a perfect encapsulation of everything Eggman represents. 

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Not only is that some great context for a first rival, it just makes for a compelling character all around. Metal Sonic doesn’t have a personality of his own other than “grab girl, run fast,” so this adds weight to giving Sonic a rival. 

3 Shadow: Sonic’s Longest Lasting Rival

Sonic has arguably had 3 significant rivals over the course of the franchise: Metal Sonic from 1993 to 1994, Knuckles between 1994 & 2001, and Shadow the Hedgehog ever since. Now, to be fair, it’s not actually often where Sonic interacts with his rivals in the typical rivalry way. They mainly just exist alongside each other and share unique chemistry. 

That said, it still must be pointed out that Sega’s more or less settled on Shadow as Sonic’s de facto rival. Knuckles pretty much maintains none of his original character traits, his tension with Sonic basically non-existent, while Metal Sonic has no real personality and only persisted as the main rival for that brief window where Sonic CD was out, but Sonic 3 wasn’t.  

2 Metal Sonic: An Actual Villain

Even in Sonic Adventure 2 where playing as him is literally framed as playing as a villain, Shadow doesn’t really come off like a bad guy. He’s not even the main antagonist of SA2’s Hero Story despite serving as the final boss. Shadow the Hedgehog is the closest the character has ever come to actually seeming like a villain, but the less said about Shadow, the better. 

Metal Sonic, on the other hand, fills the villain role well– especially since he’s such a clear foil for Sonic. Originally introduced in Sonic CD, Metal Sonic’s main sins were kidnapping Amy and helping Eggman usher in a dystopian future through eco-terrorism. Sonic Heroes upgrades him into the main antagonist, it turns out that actually giving Metal Sonic dialogue does him little favors. 

1 Shadow: Traditional Rivalry With Sonic

When it comes down to it, Sonic and Shadow actually have a defined relationship with chemistry. Compare Sonic’s dynamic with Metal Sonic in Sonic Heroes, to his dynamic with Shadow in Sonic Adventure 2– it’s like night and day. Not just that, Shadow represents a traditional rivalry with Sonic. 

These are two characters who are more or less portrayed as equals at this point. Shadow is the Vegeta to Sonic’s Goku, if you will. As a result, Shadow just fills the role better, developing not only as a character, but the relationship between him and Sonic. That’s something Metal Sonic lacks completely. 

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