Before Dr. Light ever constructed what would eventually become Mega Man, he first designed the robot known as "Proto Man" ("Blues" in Japan) which similar to his name was designed as a prototype of his future creations. Dr. Light's achievement greatly exceeded his expectations, however, he found a critical problem on Proto Man's power reactor. He made plans to modify and repair him, but the robot ran away, fearing that he would lose his identity and become like a different person.
Three main installments, as well as one online game, were published for the PlayStation 2 (PS2). Final Fantasy X (2001) introduced full 3D areas and voice acting to the series, and was the first to spawn a direct video game sequel (Final Fantasy X-2, published in 2003). The first massively multiplayer online role-playing game (MMORPG) in the series, Final Fantasy XI, was released on the PS2 and PC in 2002, and later on the Xbox 360. It introduced real-time battles instead of random encounters. Final Fantasy XII, published in 2006, also includes real-time battles in large, interconnected playfields. The game is also the first in the main series to utilize a world used in a previous game, namely the land of Ivalice, which had previously featured in Final Fantasy Tactics and Vagrant Story.