WARNING: Spoilers for X-Men #7 follow. The term "omega-level mutant" has gained new importance in the last few years, as the majority of the world's mutants have taken up residence on the island nation of Krakoa. House of X #1 revealed a definitive list of Marvel's omega-level mutants, and also helped defined the term as a character that has "an undefinable upper limit" that "cannot be surpassed in any measurable fashion." 14 X-Men characters fall under this definition, with familiar names such as Jean Grey, Magneto, and Storm making the cut. However, the most recent issue of X-Men teases a new addition to the exclusive club.
The main focus of X-Men #7 by Gerry Duggan, Pepe Larraz, Marte Gracia, and VC's Clayton Cowles is the secret origin of Captain Krakoa, a new identity for Cyclops after he's resurrected. A page at the very end of the issue turns our focus on Omega-level mutants when Dr. Cecelia Reyes updated Synch's medical file. During the X-Men's battle with Dr. Stasis' human-animal chimeras, Synch and Sunfire work together to rescue innocent civilians. As his name states, Everett Thomas' mutant abilities allow him to "synch" with any mutant in his vicinity to borrow their powers. The only members of the X-Men at their Treehouse base of operations were Cyclops, Synch, Sunfire, and Wolverine (Laura Kinney). Jean Grey, Polaris, and Rogue were off-planet on Arakko. However, even with Synch and Jean being planets apart, Synch was still able to borrow Marvel Girl's telekinesis to contain and put out a blazing fire.
The physical strain forced Synch to pass out afterward, but that doesn't disqualify the massive achievement. As Dr. Reyes notes, it's highly unlikely that Synch reached out over millions of miles to harness Jean's abilities. Therefore, he must have retained these powers with "muscle memory." She also hypothesizes that being in close proximity to Jean in the Treehouse, along with having his baseline powers enhanced through resurrection, has led Synch to the edge of "Omega mutant" status.
Evolving into an omega-level mutant would be a huge character development for Synch. He was one of the few mutants selected to represent Krakoa on the X-Men, and played a critical role in their infiltration of the Vault. Synch's time spend in the Vault aged his mind to over five centuries old, and he was also involved in a romantic relationship with Wolverine. Unfortunately, he's the only one of the two who remembers it. Seeing how Synch navigates this touchy subject will be a plotline to pay attention to, along with his increasing powers. If Synch can truly master retaining different abilities he comes into close proximity with, then he has the potential to be one of the strongest mutants in the Marvel Universe.