|First Appeared In||Mega Man|
 Mega Man
Dr. Thomas Xavier Light is the sole creator of Proto Man, Mega Man, and Roll along with the other robots that help Mega Man on his questing. Dr. Light created Proto Man out of sheer curiosity. He wanted to make an intelligent robot that could reason and make his own decisions while using a conscience. However, Dr. Light soon realized he produced a faulty core after it was put inside of Proto Man and offered to take it out so Proto would not die. Proto Man refused do to his fear of being changed, and ran off. Dr. Light eventually moved on, assuming Blues was dead and started working on a similar project with two robots with perfected cores. Rock and Roll were the product, and their one task was to be housekeeping robots. Rock, however, wanted to explore his side of reason and let the side of justice come out.
After Dr. Wily, Light's partner in science, ran away with the 6 newly created robots that the two spent so much time working on, Rock knew this was his opportunity to shine. He asked to help, and Dr. Light transformed him into Mega Man, a beefed up robot that was designed to fight-for justice. Dr. Light's role was done, and now Mega Man would have to do what he did best.
 Mega Man X
Dr. Light had a similar role in Mega Man X. His goal was to create a robot that was stronger, faster, and better than anything he'd ever done. He got to work and created Mega Man X. Although the games pick of much after Light's death, we still see him in holograms inside of capsules to give X his weapon upgrades and armor abilities that are a staple in what makes X more powerful that Mega Man.