Everett Thomas was a mutant born in St. Louis, Missouri. He possessed an aura which allowed him synch up with other superhumans in his immediate vicinity, thereby briefly gaining any powers they possessed.
The mechanical collective race known as the Phalanx had assimilated the X-Men and attempted to wipe out what was to be the next generation of mutant heroes: (Husk, Jubilee, Monet, and Blink). Synch had accidentally synched to Banshee, who was in the area, and had shattered all the windows in his area with Banshee's "borrowed" scream. He didn't know how he did it, but the next thing he knew there was a slew of police officers with guns pointed at him. Unfortunately for them, the menace wasn't Everett, but the Phalanx, who attacked the officers. Luckily, he was saved thanks to the help of the Emma Frost, Sabretooth, Banshee, and Jubilee. This misfit band of heroes ended up saving the other kids who were attacked by the Phalanx. With the sacrifice of Blink, they managed to escape.
Following the end of the Phalanx crisis, Everett and the other youths were all relocated to the Massachusetts Academy, where they trained to use their powers, received a formal education, and acted as the next generation of X-Men, Generation X. During his time with Gen X he was briefly transformed into a voracious parasitic mutant by the team's arch-nemesis Emplate who wanted to destroy Synch's happy family life. Under Emplate's influence, Synch menaced his family and friends until M, who he had difficulty synching with, was able to defeat him.
When Emma Frost's sister, Adrienne, came to America, she forced Emma to re-admit her back into the school. If not, Adrienne would release information to the parents of the normal kids that the Xavier School For Gifted Youngsters was a secret training ground for mutants. During this time, Synch began a relationship with his team-mate M and became one of the few people she would open up to. Later, Adrienne stirred up mutant hatred amongst the human students in the school. When the parents of the non-mutant students heard that their children were going to school with mutants, they all arrived together to take their children away from the academy. However, Adrienne Frost had planted bombs all around the school. Banshee and Synch set out to turn off and deactivate all the bombs, while Emma and Adrienne brutally fought. Eventually, Emma pulled out a gun and shot Adrienne, killing her.
Meanwhile, Banshee and Synch separated. Synch found a bomb and there were human students nearby. Everett "synched" with the nearest mutant, Monet. However, Monet was too far away, so he only received a portion of her powers, which happened to be her super strength. Using all his might, he threw the human kids out of the room, saving them from the explosion. Sadly, he wasn't able to save himself, dying to save his human peers.
Synch was many years later among the many mutants temporarily resurrected by Eli Bard's Transmode Virus to serve as part of Selene's army of undead mutants.
Years later, Synch resurfaced in the newly-founded mutant nation of Krakoa, having been presumably reborn by the hand of The Five, a group of mutants capable of combining their powers into a process of resurrection, brought together by Charles Xavier as part of his plans for mutant ascension.
* Max stats represent potential using mimicry ability
Synchronicity:He possessed an aura which allows him to be "in synch" with other superhumans in his immediate vicinity, thereby gaining any powers they possess. The powers Synch "synchs" will fade some time after the superhuman he is "in synch" with leaves the vicinity. When Synch uses his powers, a multi-colored aura appears around his body. The aura is caused by the energies he is absorbing splitting the ambient light around him, which causes the described effect.
In a number of cases his manifestation of their powers may be more powerful or versatile, such as flight while synched with Chamber or his aura becoming a protective shield while syncing Penance.
Aura Tracking: He was able to track other mutants by allowing his aura to lock on to the mutants bio-signature, and the aura will extend in the general direction in which the mutant is located.
It had been theorized that, with practice, Synch would have been able to permanently retain these powers and abilities he acquired.
On one occasion Synch apparently duplicated Spider-Man's powers when both were exposed to a mutagenic pollen from Plantman. This seems to be the only instance of him syncing with a non-mutant.
He was also able to synch with Gaia, a mutant but not necessarily a human one.