Thomas Lightner first appeared as Blacksun in Marvel Two-in-One #21-23 (November 1976-January 1977), and was created by Bill Mantlo and Ron Wilson.
Lightner released Nuklo and allowed Thundra and the Grapplers in to cause some damage and distract the facility's staff.
[volume & issue needed] Lightner was supposed to use the Nth Projector to send the Project: Pegasus facility into another dimension, but instead used it on himself.
All of the heroes at the facility were absorbed into him, and Wundarr the Aquarian was able to use his null field to shut off the Nth Man's powers.
[2] During the battle, Lightner exchanged places with the infant child of Squadron member Arcanna and was thereby able to return to his own form; he became the new Wizard Supreme[3] and eventually took the name "Mysterium".