Warning: The following feature contains SPOILERS for The Flash, season 6, episode 10, "Marathon."
The first post-Crisis episode of Arrowverse, but it was not the classic character from the DC Comics books. Ironically, the original Crisis on Infinite Earths story also introduced a new Dr. Light, but that character was more of an anti-hero than a villain.
First appearing in Justice League of America #12 in 1962, Dr. Arthur Light was a physicist who developed a special suit that allowed him to control light in any form. This gave him a variety of powers including fashioning holographic illusions, becoming invisible, generating lasers, and creating force-fields made of compressed photons. A retcon in 1989 established Light as a former employee of STAR Labs, who stole the suit after killing its inventor, Jacob Finlay. The guilt of this act is believed to have driven Dr. Light mad, as he became convinced that Finlay's ghost was haunting him and that only the light of the suit could keep the spirit at bay. Whether the ghost was real or not, it was agreed by most of the heroes who fought him that Dr. Light wasn't the brightest bulb in the pack.
Reference was made to Dr. Arthur Light in the Dr. Light was introduced during the season 2 of The Flash, who was the Earth-2 doppelganger of Barry Allen's ex-girlfriend Linda Park. This Dr. Light possessed the same powers as Dr. Arthur Light in the comics, but as a metahuman rather than through a special suit.
The new version of Dr. Light introduced in The Flash, season 6, episode 10, "Marathon," was also a metahuman, but one who was dependent on technology to focus her powers. Using his Who's Who Binder of Villains, Cisco was able to identify the assassin trying to murder Iris West-Allen as Dr. Kimiyo Hoshi; a Japanese astronomer who had the metahuman ability to generate enough energy to fuel a star but no capacity for focusing that power in a controlled fashion. Reported missing four years earlier, Cisco theorized that Dr. Hoshi had been abducted by the same organization that created Ultraviolet and trained in the use of a stolen photon gun that used her unique bio-energy as a power source. Now armed with the ability to disintegrate nearly anything in seconds, Cisco described Dr. Hoshi as "a brand new, more powerful, murder-happy Dr. Light."
It's no coincidence that Dr. Hoshi should be introduced into the Arrowverse so soon Supergirl.
It remains to be seen if the Arrowverse version of Dr. Kimoyo Hoshi can achieve a similar sort of redemption, but her battle with Frost in "Marathon" suggests it is a possibility. Nevertheless, it is frustrating that The Flash won't bring the original Dr. Light into the Arrowverse to give Barry Allen and his allies a run for their money. Earth-Prime is big enough to more than one Doctor Light and he can hardly be worse than the Titans' version of the character.
