Doctor Sivana of Earth-E
From superman.nu: Supermanica
The Earth-E counterpart of Doctor Thaddeus Bodog Sivana who briefly battled the Super-Sons with a rifle like weapon that he reffered to as his "Negative Meson Disintegrator Beam" in a 1980 chronicle (WF No. 263, Jun/Jul 1980: "The Final Secret of the Super-Sons").
