John Proudstar was a young Apache ashamed of the dying spirit of his people. So when Professor X came calling and challenged him to be a true Apache warrior, John could not refuse the offer to join Xavier's new team of X-Men. With mutant powers of enhanced speed, strength and stamina, Proudstar embraced his Native American heritage and took on the codename of "Thunderbird". Unfortunately, Thunderbird's resilience and invulnerability were not enough to save him on the new X-Men's second mission.