History of character is unknown.
- This version of Mastermind, including all history and corresponding appearances, was initially erased from existence following the collapse of the original Multiverse in the 1985-86 Crisis on Infinite Earths limited series. However the ending of Convergence retroactively prevented that collapse, saving all the alternate realities, though in an "evolved" form. Even though versions of the character may have since appeared, this information does not apply to those versions.
- Enemy of the Challengers of the Unknown
- Appearances of Mastermind (Earth-One)
- 1 Images featuring Mastermind (Earth-One)
- Quotations by or about Mastermind (Earth-One)
- Character Gallery: Mastermind (Earth-One)