Devos is an extraterrestrial vigilante dedicated to bringing peace to the universe, but holds the rather warped view that this can only be done by destroying anyone whom he deems a threat to galactic peace—therefore, killing everyone capable of waging war. While Devos is willing to make alliances with other villains in order to further his goals, he inevitably betrays his allies (as they too are capable of waging war).
In his first appearance, he battled the Fantastic Four, then fled in his escape craft while his starship was destroyed. He then encountered and joined forces with Paibok the Power Skrull. He watched Paibok alter Lyja's genetic structure, then arrived on Earth with Paibok. He joined Paibok and Lyja the Lazerfist in an attack on the Human Torch in New York City.
His most notable act is probably his destruction of the Skrull Throneworld, throwing the Skrull Empire into civil war.
Devos later reappears in the Annihilation miniseries in the pages of Ronan. On the planet Godthab Omega, he was attacked by Talos the Untamed and later captured by Glorian. Devos conferred with Talos, who realized that Glorian was the one-time pupil of the Shaper of Worlds. When the planet was overrun by the Annihilation Wave, Glorian was distracted, releasing Devos and Talos. Ronan ordered the two of them to the spaceport to get off-planet with any other survivors.