Doctor Spectrum battles the Avenger Iron Man, and is defeated when the hero deduces that the villain's Power Prism (a sentient entity called Krimonn) is vulnerable to ultra-violet light.

No longer worthy to wield the hammer due to him being tainted by the gem, Thor drops Mjolnir and reverts to his mortal alter-ego Donald Blake during a fight with Iron Man, which results in the Power Prism losing control and becoming inert.

[6] The Grandmaster later reforms the Squadron Sinister, bringing in Henry Pym's former lab assistant Alice Nugent to be the new Doctor Spectrum.

[9] Roy Thomas and penciller John Buscema created an alternate-universe team of heroes called the Squadron Supreme, who debut in The Avengers #85 (February 1971).

[12] The Squadron are mind-controlled by the entities the Overmind and Null the Living Darkness, but are freed by the Defenders and aid the heroes in defeating the villains.

[15] Gruenwald, Ryan, and inker Al Williamson created a graphic-novel sequel[16] which maroons the team in the mainstream Marvel universe.

The title Supreme Power relates how Joseph Ledger, a soldier in the United States Army, accidentally bonds with a crystal found in the vessel that brings Hyperion to Earth.

[22] The story continues in the limited series Doctor Spectrum, written by Sara Barnes and art by John Dell and Travel Foreman, with the experience placing Ledger in a coma, and after reliving his life in his mind for the benefit of the apparently sentient crystal, the character awakens and adopts the codename of Doctor Spectrum.

[23] Operating in a military-style uniform as opposed to a prismatic costume, Doctor Spectrum encounters and battles Hyperion, forming a truce with him to hunt down super-powered serial killer Michael Redstone.

[28] In the team's first mission, Doctor Spectrum led the Squadron Supreme of America in fighting Namor and the Defenders of the Deep, when they targeted a Roxxon oil platform off the coast of Alaska.

[30] In The War of the Realms, Joseph was at his desk until he and the other members of the Squadron Supreme of America were summoned to Washington D.C., where Phil Coulson brought them up to speed with Malekith the Accursed's invasion.

Doctor Spectrum leads the Squadron Supreme of America in fighting an army of Rock Trolls and Frost Giants.

[28] Doctor Spectrum led the Squadron Supreme in an attempt to apprehend Black Panther, when he infiltrated the Pentagon to confront Phil Coulson.

[4] When the Grandmaster requires champions to battle the Avengers, he retrieves the prism and grants Krimonn several energy-based powers that can be used in conjunction with a host.

[citation needed] When the Power Prism later exploded and fragments of it were embedded in Doctor Spectrum, his skin, hair, and costume were bleached chalk-white.

[26] An alternate, female version of Doctor Spectrum appears as a member of the Great Society, a team of Justice League analogues from Earth-4290001.