After the recent Marvel Comics' X-Men #7 actually revealed that one mutant, Synch, is starting to develop into an Omega-level mutant, many X-Men fans have spent months debating whether or not it could be true. After all, only 14 Krakoan mutants, including Iceman and Storm, have been explicitly declared Omega mutants.
But an "Omega-level mutant" tends to be defined as a mutant with no upper limit to the potential of their powers. If it is true that Synch might have developed Omega-level capabilities thanks to his resurrections, there may be other mutants who have earned the right to claim the Omega title.
Synch
After recently being resurrected after one of the worst X-Men losses in the comics, Synch came back to life with five centuries of experience under his belt, thanks to his time in the Vault. As a mutant with power replication abilities, Synch was originally restricted to mimicking mutants, and only if they remained in his vicinity.
Yet, after the Vault, Synch developed the power to mimic non-mutants and to hold onto the powers even after the person he was "Synching" left his vicinity. Now, with increased capacity for his powers, it's likely that Synch's upper limit can't really be defined. After all, his powerset is growing by the issue, and even Cecilia Reyes can't figure it out. All that considered, it's likely Synch is an Omega-level mutant.
Rictor
Another often-underrated mutant, Rictor is someone with a strong connection to the Earth that allows him to cause seismic events and reshape the Earth itself. Essentially an earthbender, Rictor can also control lava, plants, and anything else connected to Mother Nature.
Given his connection to the druids, Rictor is proving to be one of the most powerful magic s in Marvel as well, and is growing in power exponentially thanks to his bond with the Earth. If an Omega-level mutant lacks an upper limit, Rictor is smashing through his limit with every appearance and proving that he truly deserves to be recognized as a powerful mutant.
Box
One of many Marvel characters that have been forgotten through the years, Box is a mutant with the power to reshape and control all non-organic materials. This has been interpreted in many ways, but most often allows Box to do whatever he likes to any non-living thing, whether that means ripping microplastics out of Sabretooth or literally bringing crystals to life on another planet, as he does in one of his earliest appearances.
If Magneto is an Omega-level mutant simply for his control over magnetism, Box's limitless control of non-organic matter absolutely should put him on the list. If he was a more popular character, it's likely he would have been included years ago.
Triage
If Elixir is an Omega-level mutant, thanks to his healing powers, Triage should be too. With the power to manipulate the life force of those around him (and himself), Triage has used his powers to temporarily reanimate the dead, permanently restore the dead to life, and potentially ensure his own immortality.
Though Elixir is considered Omega-level, he can only restore the dead with the aid of the Five. If Triage can do it on his own, and naturally maintain his immortality where Elixir cannot, it makes much more sense for Triage to bump Elixir off of the "limitless power" measurement.
Northstar
As the fastest X-Man in Marvel Comics, Northstar has often been the subject of debate when it comes to Omega-level mutants. With the ability to move at upwards of 189,000 miles per second, Northstar could split the world in half simply by flying around it. Though the effort would kill him, it's possible that — given it's impossible for him to test his limits — he could move even faster.
It's unlikely that Northstar's speed will ever be sured, as it's physically impossible for any mutant to break the speed of light without dying in the process. With that being said, it's probable that Northstar is simply an unexplored Omega-level.
Darwin
Not every mutant has powers that make them a hero. In fact, Darwin's powers at times make him anything but. With the power to adapt to survive anything, Darwin's abilities really can't be sured by any other X-Man. Whether it means teleporting away at the first sign of trouble, growing gills, or shooting lasers, Darwin has the power to do it all.
Though he was a mutant failed by Fox's X-Men franchise, he is an absolutely incredible character who deserves his place on the Omega list. Even if another mutant can adapt the way he can, they can never sur him. His ability to survive is limitless, and that's why he deserves the spot.
Lifeguard
A mutant with the power to save lives, the aptly named Lifeguard can develop any ability necessary to save any life, be it her own or another's. If that means turning into metal, growing wings, or shapeshifting, Lifeguard will develop that power and subsequently save a life.
As what essentially amounts to a stronger version of Darwin, Lifeguard doesn't really get the reputation she deserves. No mutant can ever sur her ability to save lives, as their mutations are often tailored to other specific niches. With no upper limit to determine how she can shift, Lifeguard deserves her place among the Omega-levels.
Wolverine
Wolverine is the best he is at what he does, and what he does is heal himself. With a natural and uncontrolled regenerative healing factor that gives him the power to survive almost any wound, Wolverine is practically impossible to kill. Resistant to the effects of aging, poisoning, and even vampirism, it's hard to put a stop to this old dog.
While Wolverine has died in comics before, his healing factor usually means he can easily come back and put an end to whoever took him down. To make matters even weirder, his Adamantium bones actually slow down his healing factor. Without them, his natural regeneration would be so powerful, it would be impossible to stop him. With that in mind, he definitely deserves to call himself Omega.
Rachel Summers
Though Rachel Summers wasn't included on the Omega-level list provided by the franchise, she was actually the first mutant to ever be referred to as being Threat Level Omega. Rachel actually spent over a decade bonded to the Phoenix Force, having been the daughter of a Jean Grey who never developed into the Dark Phoenix.
As one of the most powerful X-Men telepaths and the only mutant in Earth-616 to avoid corruption by the Phoenix, Rachel absolutely deserves a spot among the Omega-levels. It's honestly shocking that the character wasn't included in the first place.
Eye-Boy
Another member of X-Factor, and one who has a seemingly underwhelming power, Eye-Boy is exactly as his name describes: A boy with a lot of eyes. With a physical mutation that left 57 eyes scattered across his body, Eye-Boy has an incredible perception that lets him see at a microscopic level, access night vision, and even see in infrared.
With the ability to read people's body language to predict their behaviors, and with the ability to perceive magic, Eye-Boy could definitely be categorized as an Omega-level mutant. In fact, Professor Xavier even implied as much and requested that Northstar keep him updated on Eye-Boy's development. Though Northstar refused, it's a pretty clear indicator that something special is happening with Eye-Boy's powers.
