In his first appearance, Doctor Light attempted to rob a gold transport. He ended up fighting the Teen Titans, where he easily defeated Cyborg, Robin, Starfire, and Beast Boy. Raven, however, became so enraged at him that her dark side manifested; she almost killed him when she attempted to drag him into the darkness under her cloak. Once Robin stopped her before any fatal damage could be inflicted, the event left Doctor Light severely traumatized in deep state of shock.
However, even this trauma did not stop him from continuing his criminal career, although it did seem to reduce his ability to be an effective villain. In his next scheme, he attempted to drain the oil reserves on an abandoned drilling platform to supercharge his suit, overlooking the fact that the platform was in direct line of sight ofTitans Tower. The Titans promptly responded, and when Raven chose to confront him again with the appearance of this form ( "Remember me?"), and Doctor Light meekly surrendered ("I'd like to go to jail now, please").
Months later, Light attempted to steal money from the bank vault in the Bank of Perez, but was stopped just in time by the efforts of Robin, Starfire, Cyborg, Beast Boy, Raven, Bumblebee, and Aqualad.
Doctor Light later appeared as one of the recruits of the Brotherhood of Evil, but did not participate in any of the Brotherhood's plans, instead deciding to work on his own. He retreated to the Arctic Circle where he build an amplifying device to channel the power of the Northern Lights into his suit. When the Titans destroyed the synthetic diamond serving as the machine's collector, Doctor Light subsequently kidnapped Kole and used her crystal body as a replacement. While the machine did increase his powers to previously unmeasured magnitudes, he was defeated by the combined efforts of Gnarrk, Kole and Starfire, who damaged his suit critically, shedding its power.