Somewhere in the depths of space, a United States space shuttle collided with a mysterious rock and the reminant energy created by the House of M|Scarlet Witch's recent alteration of reality. When the shuttle crashed to Earth, a powerful mutant emerged and was subsequently detected by Emma Frost and Cerebro, in the process overloading Emma with psychic feedback. A team of X-Men were dispatched to the crash site, and the mutant attacked them upon arrival. After incapacitating Wolverine, the mutant absconded with Cyclops and Marvel Girl (Rachel Summers) to an old research facility used by Moira MacTaggert. The mutant seemed to have some knowledge of past X-Men and their history, in that he was able to recognize Cyclops but did not know later members such as Wolverine and mistook Marvel Girl for her mother, Jean Grey.
Using Sway's powers in combination with Marvel Girl's, the mutant began taunting the captured X-Men with images of the past. Meanwhile, Banshee uncovered the location of a secret tape with information about the new mutant but was killed by the Blackbird while delivering the tape to the X-Men. The Beast was, however, able to retrieve the tape, and the X-Men which contained revelations that the mutant, under the codename "Kid Vulcan" was part of a forgotten team of MacTaggert's students conscripted to help rescue a group of X-Men trapped by the sentient island Krakoa, some years ago. The mutant, now using the code name "Vulcan," also revealed to Cyclops that he is his youngest brother. After releasing the second presence within him with the help of Marvel Girl a mutant named Darwin manifested who was apparently comatose. While fighting former heroes the X-men Vulcan left Earth denouncing Cyclops as his brother with his mind intent on destroy Emperor D'ken and the Shi'ar Empire.
After confronting and destroying Shi'ar ships near Earth, Vulcan began using stargates to lead him to Shi'ar space, he also used his powers to produce an electronic voice for himself so that he could communicate with the ships in the vacuum of space. Once he realized how far he was, he took control a starship and forced its captain to teach him about the Shi'ar Empire. The captain eventually led Vulcan to a planet where he was ambushed by the Imperial Guard. Though he was much more powerful than them Vulcan was eventually defeated, and he lost his left eye in the process. In jail, his captors gave him a bionic eye, but left him alone for the most part. Vulcan began to hallucinate, seeing himself at his true calendar age of 15. Soon, however, he was released from his cell and directed to another inmate, whom he freed, finding it to be none other than Deathbird, who managed to set aside Vulcans personal vandetta and started a relationship with him. Deathbird took Vulcan to the planet on which her comatose brother D'ken was residing, and for her love, Vulcan healed D'ken's broken mind. Vulcan then assisted the revived D'ken in a coup against Lilandra, though the Majestrix escaped with the X-Men and Starjammers. Recognizing both Vulcan's danger and his sister's love for the human, D'ken next made the shocking suggestion that Vulcan marry Deathbird and join the Royal Family.