The Megaman Story Because Legends 3 is coming out, this is pretty helpful.

[Forte 0]

With the advent of Legends 3 fast upon us, I feel it's necessary to, for those who are not familiar with it, cover the story of the Mega Man (RockMan) series. I do my best to keep my information based as much on official information and logical conjecture as possible, but not everything in this timeline is one-hundred percent accurate. The story of the RockMan series is pretty simple and self explanatory for the first six games. Dr. Wily is trying a new evil plot and you must defeat his eight robot masters to save the world. Straightforward and easy. But at around RockMan 7, the series begins to develop a story: (all Japanese names used, aside from "Dr. Right" who Capcom confirmed is correctly called either "Light" or "Right")~~Possible SPOILERS ahead. Please do not read if you're not comfortable with facts regarding the ending of various RockMan games.~~7: Wily creates Forte by harnessing a new energy source he dubs "Fortenium". The nature of this energy isn't clearly defined, nor is it truly important to the series at this time. It later, though semi-unconfirmed, does become important.8: Duo, an alien robot and an evil robot fight in outer space, where their battle leads them both to crash on Earth. Wily harvests what Duo calls "Evil Energy" from the wrecked evil robot. This energy source is capable of giving robots insane strength, though it apparently also causes them to lose their humanlike logic. This energy is confirmed by the Zero Collection timeline to be the original Maverick Virus Towards the end of the game, Forte acquires and uses evil Energy to perform a more powerful fusion with his dog, Gospel, than the one that Dr. Wily built into him in 7.8.5 (RockMan and Forte): Wily creates King to lead an army of all previous robot masters against RockMan. Forte intervenes out of rage induced by Wily's creation of a "superior" robot. Due to the inclusion of a Gospel fusion form like the one used in 8, it is likely that Forte kept the evil energy and has learned to control it to an extent. Forte's ending, showing Wily's plans for "King 2.0" most probably later became Zero.9: Filler sidestory, though it does introduce for the first time the concept of robots having expiration dates and a slight hint at the fact that robots, like humans, possess a desire for self preservation above all other things. Without a doubt, this is the only main series game to prove that the robots of the classic series are, to a certain extent at least, self aware and capable of acting on their own desires. 10: Dr. Wily creates the Roboenza virus, a virus that gives robots flu like symptoms. It is worth speculating that this virus was manufactured through the use of what little evil energy Wily had left. The interesting part about this virus is its ability to be communicated like a human virus, and if the ending of 10 has anything to say about it, can be caught by humans, too. (Wily probably just had a cold.)Somewhere in this mess, Wily starts work on Zero, more than likely using the evil energy to modify Fortenium into a stronger energy source. According to the Zero Collection timeline, Zero is activated shortly after his finalization, though he was destructive and refused to listen to orders. Wily places him back in stasis, probably pissed that yet ANOTHER robot won't listen to anything he says.If it took a while for Wily to create Zero, at least in comparison to RockMan World II (the second gameboy game, which according to the game manual, Wily went forward in time 37 years), it is a reasonable assumption that due to Rock's destruction of Quint, his future self, the future is sadly RockMan free. This, coupled with the inevitable death of Blues (An energy system malfunction mentioned in an arcade game), the world has no hero if Wily does try anything stupid. These events most certainly lead Light to create X if nothing else did. X is completed and put through a series of tests that were to be completed ~100 years after his creation.X is awakened, Sigma is created based on X's design, a new type of robot - "repliroid" is created. These robots are capable of making their own decisions and carrying out life as they see fit. (Don't really see how this is any different from the robot masters in the classic series since in general, they seemed to be free to do as they pleased, especially if Super Adventure RockMan is any indication). Malfunctioning repliroids and mechaniloids are classified as the original "mavericks" and an agency to put and end to malfunctioning units, the "Maverick Hunters". Of these original Maverick Hunters, Gamma and his unit were sent out to search for and eliminate the cause of an abnormal energy source, believed to simply be a malfunctioning repliroid. Communication with Gamma's unit is lost. Sigma is sent with a small group to investigate Gamma's disappearance, And Sigma confronts Zero. Through contact with Zero, Sigma becomes infected with the same virus that made Zero's cognitive functions go awry, though due to Sigma's radically different programming, the virus undergoes a mutation similar to human viruses. This virus is later called the "Sigma Virus", as Sigma was its first known carrier.X6: Human scientists finally determine that Sigma's virus is only a small part of the overall problem and isolate the spread of the Maverick Virus to Zero. Zero is asked by these scientists to undergo tests that may take quite a while. He agrees in order to protect the world he has fought to rid of the virus. These scientists determine that it will be easier to study Zero and create an antivirus by separating his body from his mind. Zero's mind is taken from his body and researched separately.A human scientist researching Zero's mind finds a cure for the Maverick Virus and creates the Mother Elf, a sentient program that can remove all traces of the maverick virus from any infected robot. The Maverick Virus is completely cured, thanks to efforts from X and the remaining Maverick Hunters. Scientists who had previously researched the Maverick/Sigma Virus shifted their focus to the creation of other cyber elves.The Zero series begins. Zero is reawakened by a small resistance of repliroids who fight against the now corrupt global government. Zero agrees to help them to find out who he truly is. During his time he meets Copy X, a creation of Ceil's meant to replace the former X, who gave his life to seal away the Mother Elf, who had, due to overuse, become basically the only carrier of the Maverick virus in the world.Dr. Vile, a former human scientist finds a way to crash the prison chamber he was in, called "Forbidden Ark" back onto the planet. He escapes along with Omega, a powerful weapon repliroid created during the end of the Maverick Wars. Vile creates his own Copy X and assumes indirect control of Neo Arcadia, cementing power over the world. Zero and the resistance remove him from power and destroy Omega, who is revealed to be Zero's original body. Vile retreats to Ragnarok, a space station armed with a powerful laser. Vile sets the laser to destroy Neo Arcadia, aimed right at its center. Neo Arcadia is almost completely annihilated and much of the population of the inner-most parts is wiped out. Zero travels to Ragnarok and fights Vile for the last time, sacrificing himself to make sure that Vile falls to earth with him.Of particular interest, Dr. Vile is the first character to be confirmed by a game to have been converted from human to robot. The only other three to openly admit this are the Sage Trinity of Legion: Master Albert, Master Thomas, and Master Mikhail.It's logical to assume that "The Master" of Legends fame, creator of Elysium, the Irregular Hunters to which Trigger belongs, the System units, and the carbons themselves, was once a Sage of Legion. Legends refers to him as the last true human, but it also puts his age at around 3000. This is only possible if The Master was actually a human converted to repliroid like the Sage Trinity in ZXA, which, for what it's worth, has such an unclear definition of what "human" and "repliroid", calling The Master human isn't necessarily incorrect even if he were a repliroid.