Quasar is Phyla-Vell, though she didn't start out that way. Phyla was artificially created by her 'mother' Elysius of Titan, and is the genetic daughter of Mar-Vell, the first Captain Marvel. She was the second of his artificial offspring, following her genetic brother Genis-Vell, who inherited the title Captain Marvel following the original's death, and Phyla herself bore the title for a time, stemming from a conflict with her then-insane brother (he got better)... long story short, she's had a lot of expectations to live up to.
Marvel's Annihilation mega-series added another legacy for her to grapple with, as Phyla came into possession of the Quantum Bands, the powerful cosmic weapons worn by Wendell Vaughn, aka Quasar, who had been defeated and killed by Annihilus. Following the eventual defeat of Annihilus, Phyla decided it was up to her to take on the mantle of Quasar, 'Protector of the Universe', that Vaughn had upheld for so long. Along with her lover Moondragon, freed after being kidnapped by Thanos as a bargaining tool during Annihilation, Phyla set out to help rebuild the vast stretch of galaxy devastated by the Annihilation War. As well as the demands of controlling the vast powers she has inherited, Phyla is beset by her own doubts about whether she deserves the title and mantle she has taken on - all her life she has been in the shadow of her father, the first Captain Marvel, and now she must also live up to the legacy of Wendell Vaughn, whom she greatly admired as a hero. For all the good she does, she often struggles with the fear that she'll never be as good as her illustrious predecessors.
Phyla has also become known as one of Marvel's most prominent lesbian characters - perhaps the most prominent, given her central status to Annihilation's sequel, Annihilation: Conquest. Her attraction to Moondragon (Heather Douglas, a human trained in combat and psychic power by the Titans) was first established in the Captain Marvel title, and by the time of Annihilation the pair were openly a couple. Their relationship - one of mutual love and support, especially in the chaotic aftermath of Annihilation - has been the cornerstone of Phyla's Annihilation: Conquest miniseries, and Phyla's saving grace in her inner struggle to live up to Quasar's name has been Heather's guidance, reminding her not to over-idealise Mar-Vell and Vaughn, or to overlook the good that she does. With the sudden, devastating Phalanx conquest consuming the Kree Empire, Quasar and Moondragon are among the few to escape enslavement, and in spite of her doubts, Phyla - with Heather always at her side - doesn't hesitate in answering the call to save the galaxy, even when the enemy seems unstoppable.
Phyla-Vell, the current Quasar, is currently appearing alongside Moondragon in Marvel's Annihilation: Conquest - Quasar miniseries, and is slated to take a leading role when Annihilation: Conquest itself begins next month. She and Moondragon appeared in Annihilation (which Marvel is publishing as three softcover trade paperbacks, following earlier hardcover releases), as well as Captain Marvel in 2004 (issues #16-25), and at the trial of Starfox on Titan in She-Hulk #12-13.
