Characters on Mega Man's side:Nick Fury, Mega Man, Darci Roll, Supergirl, Black Panther, Wolverine, Storm, Shadowcat, Rogue, Professor X, Ice Guy, Phoenix/Jean Grey, Beast, Cyclops, Angel, Nightcrawler, Mr. Fantastic, Invisible Woman, Harley Quinn, Deadpool, Cat Woman, The Thing, Human Torch, Spider Man, Iron Man, War Machine, The Penguin, Cyborg, Captain America, Batman, Black Canary, Robin, Black Widow and Hawkeye
Neutral for now:
Lex Luthor and Mercy Graves
Characters on Wily's side:
Dr Wily, Proto Man, Callisto, Pyro, Magneto, Lady Deathstrike, Dr. Doom, Electro, Green Goblin, Dr. Octopus, Bane, Dive Man, Drill Man, Toad Man, Bright Man, Pharaoh Man, Ring Man, Dust Man, Skull Man and two of ED-209s (in Wily's hands)
Mega Man 4: Wily's New Revenge (13th July 2065) (16-17 hours after Luthor's defeat and revelations about Wily's plans)
Only more than half a day after Luthor's last defeat and revelations about that video showed about Wily was faked, Wily returns with Proto Man, Supervillains, two of ED-209s and robot masters (those robots superheroes previously defeated in the previous part of Mega Man 4) to attack Metropolis. Those Superheroes first defeats two of ED-209s, then defeating robot masters (first Dive Man, then the other robot masters such as Drill Man, Toad Man, Bright Man, Pharaoh Man, Ring Man, Dust Man and Skull Man), then defeating Proto Man and those Supervillains (Callisto, Pyro, Magneto, Lady Deathstrike, Dr. Doom, Electro, Green Goblin, Dr. Octopus and Bane), in last even defeating Dr. Wily once more. However, Wily gives up for now. Mega Man along with those Superheroes returns to their league's home.
To be continued...