Dr. Light is a main supporting character from two series in the Mega Man game franchise.
In the Mega Man Classic series, he is depicted as an aged scientist who is a peerless roboticist and winner of the Nobel prize. He is the creator of Mega Man, Sniper Joes, several other robots, and ultimately X, whose design revolutionizes the world. While a pacifist, Light reluctantly acknowledges that the use of force is sometimes a necessity. He plays a supporting role, often developing and distributing new gear.
In the Mega Man X series, Dr. Light resumes his supporting role through enhancement capsules that contain upgrades to X's systems together with messages relayed by silver, slightly translucent holographic projections.
Dr. Light was the leading mind in the world of robotics, and after graduating at the top of his class in electronic engineering from the Robot Institute of Technology, Dr. Light devoted his life to the research and development of robots that aid in world peace. Even though his first attempt at building a humanoid robot had a fatal flaw in his energy processing device and disappeared, he was able to correct the issue with his later models: Mega Man, Roll, and the Robot Masters.
One day Dr. Albert Wily, an old school mate of Dr. Light's who had never quite been able to match his skill, reprogrammed Dr. Light's industrial robots in a bid to take over the world. Light's lab assistant, Rock, volunteered to undergo a transformation which would allow him to put a stop to Dr. Wily's mad ambitions.
Dr. Light would continue to support Mega Man every time Dr. Wily returned, creating various support items, partners and upgrades to help Mega Man on his adventures. A few times, he's been the target for kidnapping in Dr. Wily's plots.
After Wily made several attempts to conquer the world, Dr. Light noted that perhaps what robots needed in order to avoid such conflict was the ability to determine what was right and wrong for themselves, thus foreshadowing what would arguably become his greatest creation.
The last creation of the aging doctor is X, the first robot capable of genuinely independent thought and decisions. Fearful of what might happen should X go wrong, Dr. Light seals him for extensive diagnostics, knowing that they will exceed his own remaining lifespan. When X is found roughly a century later, his design is used as a basis for the reploid race of machine life.