Pyreus Kril was born on the planet Xandar, in the Andromeda Galaxy. He is a graduate of the Nova Corps Academy, the military and exploratory force of the planet Xandar. During his commission, he served aboard a Xandarian ship under the command of Gabriel Lan. Gabriel and Pyreus became friends, until Gabriel was abducted by the cosmic entity Galactus and transformed into the herald the Air-Walker. Pyreus assumes command as captain and begins an obsessive search for Gabriel. Pyreus eventually locates Galactus' vessel and confronts the entity, only to discover that Gabriel was killed in combat. Galactus tells this to Pyreus only after the Xandarian agrees to serve him as his latest herald.