History of character has not yet been written.
- This version of Mastermind, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. 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)