When Corsair and Katherine Summers Summers were kidnapped by the Shi'ar Katherine Ann was pregnant with her third child. When Christopher (eventually to become the pirate Corsair) made an unsuccessful attempt at escape, Katherine was killed and her unborn child was ripped from her womb as a punishment for disobedience. Christopher was sent off into slavery, and it was believed that the child died with her. Instead, it was kept alive and incubated by Shi'ar technology in order to make him a slave. The child Gabriel would eventually escape life as a slave and make its way to Professor X and Moira MacTaggert. Gabriel was a mutant like his older brothers Scott ( Cyclops) and Alexander ( Havok) with the power to manipulate energy. He joined a team of mutants that Moira was training in the safe use of their powers in much the same way that Professor Xavier trained the X-Men (although for a different purpose than the X-Men). Gabriel was even able to meet and train with his older brother Cyclops.
When the X-Men were sent to the remote pacific island Krakoa to investigate a mutant signal, they were quickly subdued by the island itself to use as a source of sustenance. Professor Xavier recruited Moira's team for a rescue effort. Xavier used his telepathic abilities to train the team psychically in the use of their powers. While much more prepared in the use of their abilities, the team was inexperienced in the field and also taken by the island. Of his teammates only Vulcan survived by absorbing his comrades' powers and tunneling deep into the island. Xavier recruited a second rescue team of X-Men consisting of older mutants from around the globe, and this time met with ultimate success sending the island into space. While the original team was alive and well, losing the first rescue team of X-Men took its toll on the members, particularly Cyclops because of the loss of his younger brother. In an attempt to fix his mistake Xavier removed the memory of the first team from everyone's minds. After the events of the House of M most of the world's mutants were de-powered. This sudden surge of power traveling back into the Universe caused Vulcan to awaken. Angered at Xavier's betrayal, Vulcan killed Banshee to draw out the X-Men and forced Xavier to show the team what actually happened. When the X-Men attacked Vulcan for killing Banshee Vulcan fled into space on a course for the Shi'ar empire to make them pay for enslaving him and killing his mother.
Vulcan's teammate Darwin's abilities included the ability to adapt to any scenario. When Vulcan awoke, the ambient energies of Darwin came with him. Separated from Vulcan on Earth, Darwin's life energy began to evolve him a new body. Eventually Darwin regained consciousness at the Xavier Institute for Higher Learning and learned of what had happened to his team and Vulcan.
For further reading see: Deadly Genesis
Journey to the Shi'ar Empire
Although Xavier is no longer welcome at the Xavier Institute for Higher Learning, he understands that whether Vulcan succeeds or fails in his quest for revenge, the outcome would be terrible. Xavier assembles a team consisting of Darwin, Marvel Girl, Nightcrawler, Polaris, Havok, and Warpath to fly after Vulcan in an attempt to stop him before he can reach Shi'ar space.
Deadly Genesis #1-6
The Uncanny X-Men #475-486, Rise and Fall of the Shi'ar Empire parts 1-12
Related Story Arcs
Deadly Genesis - Occurs before and leads into the events of the Rise and Fall of the Shi'ar Empire story arc.