The Atom-Master
From superman.nu: Supermanica
The Atom-Master
A renegade scientist—also referred to as the "Illusion-Master"—who is defeated in May 1959 through the heroic efforts of Batman, Robin, and Superman (WF No. 101: "The Menace of the Atom-Master!"). (TGSB)
He later resurfaces as a member of the Forgotten Villains, a team which does battle with Superman and the Forgotten Heroes (DCCP No. 77, Jan 1985: "Triad of Terror!"; DCCP No. 78, Feb 1985: "The Triad").