Determined Doctors Devise Dangerous Devices

Doctor Bruce Gordon and Doctor Charles McNider were innovative inventors, each developing gadgets and weaponry which they used in their costumed careers as Eclipso of Earth-One and Doctor Mid-Nite of Earth-Two. Primarily, Eclipso used his black diamond which projected darkness from his right-side eclipsed eye and destructive beams of energy from his left-side normal eye... while Doctor Mid-Nite used his black-out bombs to project darkness while utilizing his infra-red goggles allowing him see in daylight.

Just as McNider focused on one end of the electromagnetic spectrum with his infra-red eyewear to aid him in his crimefighting career, Gordon employed various ultra-violet projectors based on the other end of the electromagnetic spectrum to attempt purging his antagonistic alias. While Bruce met failure despite his multiple attempts at overcoming his opponent, Charles proved successful with his alter ego's adventures.

Eclipso's equipment varied depending on his various schemes, although a common feature with many of these devices was to split either himself or others into positive and negative versions of themselves. He was able to successfully able to accomplish this when battling Hal "Green" Lantern" Jordan while employing his "Murder Moon", allowing Eclipso to perpetually exist in a constant eclipse... until Jordan reintegrated himself and isolated the villain from his Gordon persona, exiling him in space.

Doctor Mid-Nite's Cryotuber had various functions, such as a liquid nitrogen freeze function, a tight laser beam and a setting which attacks his opponent's nervous system causing temporary paralysis. However, McNider utilized this device only on a few occasions in the 1960s before retiring it. 

Interestingly, just as Eclipso was able to merge and separate energized versions of himself using his and Gordon's technologies, so too McNider was able to develop a device which did something similar...only not on his world! When Dr. McNider used an experimental healing ray of his own desire to aid in the recovery of the Jimmy Olsen of Earth-Two, he then shared this technology with a visiting Superman of Earth-One, who brought the device back to his world. However, instead of just healing a test subject whom Dr. Phineas Potter had projected it rays upon, it transformed her into an energy being whom Lois Lane and the amateur superhero Human Cannonball had to corral and convert back to normal. 

It seems that some technology on Earth-Two which internalized power onto an individual does the reverse on Earth-One, amplifying that energy outside a resident of that world. So too the twin natures of Eclipso and Doctor Mid-Nite... just as Eclipso was a separate individual from McNider, Doctor Mid-Nite himelf gained a second life when he was revived from a death-like state by Wonder Woman's own purple healing ray and then transforming back into a boy after exposure to his foe Doctor Zodiac's elixir of youth.