The Better Dark Sonic

Sonic has had many "evil" duplicates, from metal copies to a sunglasses-loving criminal. When Sonic himself transforms, though, fans tend to take notice. 

Fleetway Super Sonic, Darkspine Sonic, Sonic the Werehog...none really gained the same attention as "Dark Sonic/Dark Super Sonic" from episode 67 of Sonic X. 

The scene varies between versions, however.

The main difference is that in the original (Japanese) take, Sonic seems sadder. Seeing no other option, he gives himself to hatred and destroys the "test" Meterex with an angered cry. Again alone with Black Narcissus, he simply asks if that's what the dark Meterex wanted before Eggman intervenes. 

The English version paints a very different picture. Overwhelmed by the fake-emerald's power and his anger, his personality transforms just as radically as his appearance. Where his laugh had been sort of crestfallen or nervous in the Japanese version, in the dub it turns insane. Sonic seems to relish the idea of slaughtering the "test" Meterex. He quickly takes them out in a rage and tells Narcissus to "go back to the drawing board" before Eggman intervenes.

VS

I tend to see the "subvsdub" debate as an old argument, but it does kinda' tick me off people are still whinnying that the dub wasn't a complete copy of the original. 4kids had some strict rules that seem irrelevant nowadays, but it can't be changed now. 

Regardless, I view Dark Sonic as the time the Dub whole-heartedly did a better job than the original. 

Mr. Popular

And it may be the one time the world agrees with me. Dark Sonic grew popular because of the English version, I believe. It's a bit hard to judge for a couple reasons ("Dark Sonic" is not an official name--there is no official name and much of his popularity is expressed through fan art, which isn't an obvious indication). 

• However, altering the search tools to 2005 resulted in only 2 relevant results--both of the same origin. More results, including the Sonic Wiki, came up for after 2006, which is when the dub aired. In 2014 someone even made a SFM animated version of it. 
• Though now that I think about it, the Japanese version didn't air at all...hm...google?!
  
• His personality may have inspired Gigi-D's fan creation, Tainted Sonic, or maybe it even influenced whatever the hell Sonic.exe is (Creepypasta). 
• Anyway, Sonic X's popularity in the West is credited with granting the show a 3rd season. Of the Sonic cartoons, it may be the most popular or at least most recognized, as "Gotta Go Fast" has been associated alongside Sonic to the point that it's leaked way beyond Sonic X. 
• As further evidence for Dark Sonic specifically, youtube: 
• a video from 2008 of the 4kids scene has 1,678,589 views, while a 2013 video of the Japanese version only has 5,447. 
• a newer video of the Japanese version (2017) has 15,647, but the official TMS video (with the English version, 2020) managed to gather 5,061,416 views.

Now I don't usually care about what's popular or not, but I am pointing it out because fans of the original seem a bit more vocal and it a nice reminder that not everyone thinks "the dub ruined it."

Compared

What I get from the original: Sonic gives up, becomes a slave to his anger/despair and does what Narcissus wanted. Eggman saves him from falling further into the "Black Trap."

What I get from the 4kids one: Sonic loses control and uses his rage/power to become an unstoppable force...until Eggman interrupts.   

Sonic doesn't give up, not on purpose. As Chip described it in Sonic Unleashed, "You're too strong to lose yourself." In another case, after continuing to fight against a more powerful enemy Sonic simply put it, "I just gotta' do what I've gotta' do. That's all." 

So it seems a bit out of character for Sonic to surrender to desperation. The episode its still impactful--that scream-like attack as he shreds the second Meta'creep is extraordinary. But the personality (and ergo the transformation) is not as potent. 

In the 4kids version, Sonic is overwhelmed by the energy around him/his own his emotions. The transformation seems unintentional. This is more plausible--it's a lot like what happens when Sonic turns into "Darkspine Sonic" in Sonic and the Secret Rings. 

His personality makes the real difference, with his crazed actions reflecting the darker side of Sonic's attitude. It was obvious that Sonic enjoyed that power. The quick turn from just wanting to know his friends were okay to the violence-craving was a shock. Sonic's creepy laugh is especially fitting. 

Adding to the scene are the allusions to Shadow. A hint of Shadow's 4kids theme plays as Sonic transforms. Likewise, Eggman warns Sonic that if he lets fury take control, he'll always be angry, "just like another hedgehog we know." This implies that Sonic may have become more like Shadow (or worse) if he had lost Chris/Cosmo like Shadow lost Maria (adding more depth to the event).  

So

I know how ironic it is, with "the Molly episode" right after it. But the dub did it stronger, darker, and better.  

4kids probably didn't intend to create such an intense version of Dark Sonic. They probably hoped that the shift in dialogue would make it seem like Sonic was still the hero. Instead, for about a minute Sonic was a psychopath. Oops?