Firelord first appears in Thor #225 (July 1974) and was created by writer Gerry Conway and penciler John Buscema.

Pyreus eventually locates Galactus' vessel and confronts the entity, only to discover that Gabriel was killed in combat.

[13] Firelord battles the Annihilation Wave alongside his fellow heralds, including Red Shift and Stardust.

Although wounded at one point, Firelord recovers and seeks vengeance against the remnants of the forces of Annihilus for destroying Xandar.

Like all heralds, the Power Cosmic provides Firelord with superhuman strength, reflexes and durability, flight, mastery of the electromagnetic spectrum and total immunity to the rigors of space.

[16] Firelord serves Galactus alongside his fellow heralds, with the entire group being worshipped by the Inhumans.