The origin of the man known only as Saint Elmo has yet to be revealed. He claimed to be the legenedary Keeper of the Northern Lights, and a god thousands of years old.
At some point, he came in contact with James Hudson's Department H and was recruited in the first Flight (the predecessor to Alpha Flight). One of the more battle-experienced members of the team, Elmo's largest fault was his good natured arrogance, and slight superiority complex over "mere mortals."
The team's first mission was to stop the American criminal Egghead from launching a nuclear missile into New York City from a Canadian base. During the mission, they were able to defeat Egghead and his superhuman agents but could not de-arm the missile. Faced with the imminent explosion, Saint Elmo sacrificed his life to save his team-mates' by absorbing the missile, and the force of the explosion, into himself, scattering his form.