Dazzler has the ability to transduce sonic vibrations which reach her body into various types of light. Using the light she converts from sonic vibrations, she can produce numerous effects including a bright glow all about her body and the creation of three-dimensional holograms, a blinding pulse of light on the order of several thousand watts seconds of power, a chaotic cascade of sparkling lights and colors that severely upsets other people's equilibrium, a pulsating strobe-light effect, or a laser beam, with which she can cut through virtually anything.

The months leading up to Apocalypse's first strike against America were the happiest of young Allison Blair's life. She had released her first album and had become a pop sensation. During Apocalypse's first strike, Allison's father paid to have her taken to a safe location. He did not realize the woman he paid to take his daughter out of the country was actually the shape-shifting Mystique in disguise. Mystique intended to dump her human cargo in some small backwoods town until she discovered Allison was actually a mutant with the ability to transform sound into light. Mystique delivered Alison to Magneto and she became part of his new crop of mutants training to become X-Men.

While Magneto and the rest of the X-Men were off on a mission, Nemesis came to the X-Men headquarters in Wundagore in an attempt to destroy all that Magneto had built. The Scarlet Witch gave her life to prevent Nemesis from harming any of the younger mutants in her care. Learning about the sacrifice of the Scarlet Witch, Allison decided to focus completely on becoming an X-Man in honor of her memory. During her time with the X-Men, she began a romantic relationship with her teammate Exodus and became a chronic cigarette smoker.

When the X-Men were training for their assistance in the Sentinel Evacuation of North America, Dazzler provided the hologram used in their training sessions. During their mission, the Brotherhood interfered with the migration of the humans and Dazzler apprehended the mutant Copycat who was posing as Quicksilver's deceased sister, the Scarlet Witch.

After the successful evacuation, she and Exodus were charged with the location of Nanny and Charles Lensherr, Quicksilver's brother, when they learned he had gone missing. The two of them were able to locate the remnants of Nanny in the Morlock Tunnels, but were unable to retrieve Charles. Instead, they found Gambit, Lila Cheney, and Jubilee.

Months later, Exodus was sent on a secret mission along with Wildchild, Iceman, and Morph. They have not been heard from since. Dazzler has tried to move on with her life but she secretly waits for Exodus' return, hoping he is somehow still alive.