While on an escape route through the labs in Mojoverse, a splinter team of X-Men stumbled across Mojo's genetic experiments. There, they a found a little boy that bore striking resemblances to Dazzler's recently deceased lover, Longshot. Overwhelmed with the emotions of losing her lover, as well as a miscarriage on this mission, Dazzler decided to bring the boy back to Earth with her to raise as her own. Despite most of the school's disapproval of the child's presence there, given that he was a creation of Mojo's and could very well be dangerous, Alison kept the boy, calling him Gavin.
During Gavin's teens, Dazzler regained popularity as a musician by branching out into the indie scene and soon moved to London. This resulted in him developing a passion for music itself and in no time, he had started releasing albums of his own. That came to a halt when his mutant powers were awakened, causing him to channel his own energy out as bioelectricity everytime he even so much as touched a microphone. Returned to Xavier's school, principal Ororo personally started training Gavin in harnessing his powers. During his time there, he also started going through extensive physical training but denied an X-Uniform once it was all done. His real love was not in being in an adventurer, but in being a musician.
With the president's assassination at the hands of a mutant, aggression between humans and mutants saw a rise once more. A siege from a newly upgraded Bastion on the institution saw the X-Men's numbers depleting. Gavin was asked to help out one more time by his mother and he declined once more. That was the last time he got a chance to speak to her. Losing Dazzler snapped Gavin back to the reality of the situation and he realised he could be selfish no more. He joined the X-Men in their last stand against the machine and was a crucial part in it's defeat.
The political scenario between humans and mutants has calmed down once again, but there is still a need for the X-Men. Gavin is serving as one of their ranks now, still pursuing a career in music, living in a cottage near the Xavier's Institute with his boyfriend Daniel Moonstar.
Love it love everything about it. That X is a design detail to die for.