You've probably heard dyed-in-the-wool comic geeks toss around the term "Omega-Level Mutant" before, but have they ever bothered to explain what that phrase means? The term originates from a 1980's X-Men comic (Uncanny X-Men #208) and refers to mutants with immeasurable powers.

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However, there are plenty of mutant characters in the Marvel universe that would seem like they should be Omega level, but technically aren't. It's not just about being incredibly powerful, after all, it's about having immeasurable powers... and these characters don't.

10 Rogue

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You might think that a mutant who can absorb the powers of others would fall into this category, but there are a few key factors that bar Rogue from the Omega-Level club. For one, Rogue can only borrow the powers of others through contact - meaning she has to walk up to someone like Magneto or Sunspot to do her thing.

Moreover, Rogue only temporarily possesses the powers of her victims (she hurts the heck out of anyone whose powers she steals.) At best, Rogue verges on becoming an Omega-Level mutant. If she can learn to borrow powers for longer (and without hurting people) she might have a better shot.

9 Forge

In a world in which technology becomes ever more prevalent, one might think that Forge - an underappreciated mutant technopath - would be a prime candidate for Omega-Level status. After all, a mutant like Forge could waltz into Space X and help Elon Musk unlock the secrets of the tech industry! Or, you know, the two of them would just create a better working flamethrower.

But here's the thing; Forge's powers grant him the ability to understand all forms of technology, but not necessarily the ability to control it. Forge is an excellent inventor, but he still needs resources to complete certain tasks. He can't just conjure up Gundams and Iron Man suits when he feels like it.

8 Multiple Man

Jamie Madrox's powers are more complicated than his name implies. Yes, he can duplicate himself in an instant. But his clones can create clones, and each duplicate has the potential to develop independent personalities! Sounds pretty crazy, right? Jamie isn't omnipresent, but he can get pretty close to the genuine article. So what's stopping Multiple Man from reaching Omega-Level status?

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Well, he and his clones have average stats; they're about as strong, fast, and durable as the average man. Whenever Jamie merges with one of his clones, he "deletes" that persona. This tragically happened with an infant clone that Madrox created a while back.

7 Colossus

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Colossus isn't the strongest mutant around, but he's one of the most durable. His trademark organic metal skin also makes him a standout among a sea of powerful heroes and villains as well. Couple with his adorable relationship with Kitty Pryde, and you've got one of the most mentally well-rounded X-Men on the roster.

But despite his impressive abilities, Colossus isn't remotely close to attaining Omega-Level status. He's resilient but to a fault - as numerous Sentinels and the Hulk have proven. Colossus might night need to breathe or eat when he transforms, but he does become heavy enough to sink in steep bodies of water.

6 Mister Sinister

Not only is Nathaniel Essex not an Omega-Level mutant, but he's technically not a Homo superior at all! Mister Sinister first parted with his humanity after a run-in with Apocolypse. The encounter changed Essex biologically as well as mentally - he became obsessed with mutantkind and wanted to become more like them.

Unfortunately, Essex took the dark route down this path - kidnapping mutants and forcibly merging their DNA with his own. As a result, Mister Sinister possesses a vast array of powers that he's stolen from mutantkind. Try as he might, however, Essex may never achieve Omega-Level status nor may he step from out of Apocolypse's shadow.

5 Nightcrawler

Kurt Wagner possesses the amazing ability to teleport from one location to another. That's the simplest way to explain Nightcrawler's powers. In truth, Kurt briefly enters an alternate plane of existence called the Brimstone Dimension every time he teleports. That sounds like an Omega-Level ability to us, but there are a few caveats.

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Nightcrawler can't teleport himself or anyone else to any location that he wants. To wit, Kurt's limits are about 2 miles east-to-west and 3 miles north-to-south. If Nightcrawler's powers ever reach interplanetary or interstellar heights, however, then things might be different. Either way, we still love this BAMF and his pious personality.

4 Deadpool

In truth, the most notable things about Deadpool are his popularity and his inability to shut up! DP can't teleport without his belt (that he's lost long ago) and he's not unkillable. To cut to the point, Deadpool isn't as overpowered as Marvel Vs. Capcom 3 made him out to be.

Still, you can't help but chuckle at some of DP's antics. You also have to respect the damage his R-rated films have done to the box-office. All of these things contribute to Deadpool's 'popularity armor,' a fanon power that makes characters virtually invincible so long as they have a huge fanbase. Popularity armor doesn't, however, make characters Omega-Level mutants. There's only one other mutant who's popularity armor is stronger than DP's.

3 Mystique

Raven Darkholme can mimic another person down to the most minute detail. This amazing ability allows Mystique to infiltrate all but the most secure infrastructures on Earth! Raven's used her powers to start fights with other mutant factions as well kickstart coups from the inside. But there are a few factors that keep Mystique from nearing Omega-Level status.

True, Raven can mimic the appearances of others - but her powers are only skin deep. Mystique can't replicate the powers of her marks - making it easy to discover her depending on her target. Without question, Raven's most dangerous weapon is her mind - which has helped her formulate such complex plans in the first place.

2 Wolverine

While none of the official Marvel Encyclopedias will ever mention it, Wolverine's most potent ability is his popularity armor. The guy's probably the single most recognizable X-Men in existence, despite having a powerset that's not too impressive compared to his contemporaries. By all intents and purposes, Wolverine is simply an angry Canadian with knives in his hands and metal bones. And one of his archenemies is a man that can control metal with his mind!

Despite how popular he is, Wolverine isn't an Omega-Level mutant. Regardless, we all still love him anyways - likely because of his setbacks. Most folks would run away from a battle that they knew they had no chance of winning. Logan, on the other hand, snikts his claws and dives into the fray! Wolverine's popularity armor may be thick, but he's well earned our admiration over the years.

1 Cyclops

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Thanks to his less than stellar depictions in the films, casual X-Men fans might think that Scott Summers is a joke! But that couldn't be further from the truth, at least in the comics, games, and in most animated shows. Cyclops is an original X-Man, the team's leader, and the headmaster of the Xavier institute on occasion. And none of these esteemed roles were given to Summers either - he had to earn them.

Unlike his wife and firstborn son, Scott's not an Omega-Level mutant. That hasn't stopped him from blasting Sentinels to bits, school Magneto, and wielding the Phoenix Force's cosmic power for a time!

NEXT: X-Men: All Of Marvel's Omega-Level Mutants, Ranked By Power