The Squadron Sinister plan to threaten the Earth again but are defeated once again by the Defenders and the Avenger Yellowjacket. The Power Prism is kept by Yellowjacket, who decides to modify the gem and present it to his wife Janet van Dyne (the Wasp) as a gift. Krimonn, the entity within the Power Prism, possesses Jan and transforms her into a villainous female Doctor Spectrum, who battles several Avengers but is then defeated by the Vision's use of the Prism's ultraviolet weakness (Krimonn assumed in his arrogance that Iron Man had kept that information to himself rather than sharing it with others, thus 'giving up an advantage'). The prism itself bonds to the Wasp in an attempt to save itself, but is eventually removed by Billy Roberts after he is located by the Avengers. Roberts becomes Doctor Spectrum once more, although on this occasion the Power Prism is in control and seeks to bond with the most powerful Avenger, the Thunder God Thor. The Power Prism succeeds in taking Thor as a host, infecting Mjolnir to use as a focal point to control him and defeat the other Avengers, but fails to take into account that to wield Mjolnir, Thor must be "worthy". 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, apparently forever. The Grandmaster later reforms the Squadron Sinister, bringing in Henry Pym's former lab assistant Alice Nugent to be the new Doctor Spectrum. Courtesy of a phenomenon known as the "Wellspring of Power"—an interdimensional source of superhuman abilities—the Grandmaster increases the Squadron Sinister's powers and they battle the New Thunderbolts. Thunderbolts team leader Baron Zemo defeats the Grandmaster, and in the ensuing chaos Doctor Spectrum and the members of the Squadron Sinister scatter and escape. Squadron Supreme Roy Thomas and penciller John Buscema created an alternate-universe team of heroes called the Squadron Supreme, who debut in The Avengers #85 (Feb. 1971). After an initial skirmish with four Avengers, the teams unite to stop a common threat. The characters (including Doctor Spectrum) were identical in name and appearance to the Squadron Sinister, which caused confusion in Marvel's production department, as the covers of The Avengers #85 and #141 (Nov. 1975) advertised appearances by