There's no doubt that a lot of fighting-game fans are excited for the release of Marvel vs. Capcom Infinite this year, and a massive leak citing all the characters as well as incoming future Capcom games has come out online. Though reception of the leaks has been well-appreciated, there are some that think all this news is too good to be true.
YouTube user Maximilian Dood, has expressed his excitement over the characters that have been supposedly leaked like Captain America, Spider-Man and Captain Marvel, but the mention of some other characters may less legitimate then others. Marvel's Fin Fang Foom is said to be in the roster and judging by the gigantic size of the character, it could be the game's way of harkening back to the gigantic boss fights in past games like Apocalypse, Onslaught and Galactus.
Then again, the character isn't considered to be as popular as some of the other characters in the roster, so it's possible that this could be a false leak - even Squirrel Girl is in the supposed roster, and though she is getting more attention now, she's still far away from being considered as a character with instant recognition from the general audience.
Rathalos from Monster Hunter has also been included in the leak, and it's considered that he could be the Capcom roster's equivalent of Fin Fang Foom. Dood has reported, however, that there have been some developers from MH that didn't want the character appearing back when MvC3 was being made. So it's either they've changed their minds, or this is a false leak.
PVPLive has also called the list fake, citing several red flags. Aside from the giant playable characters, there are also characters mentioned that come from very old Capcom games like Breath of Fire and Power Stone. Then again, there has been a mention that Power Stone is going to be revived this year, and lesser-known characters have come to the game before (e.g. Shuma Gorath and Jin Saotome)
Aside from the characters mentioned in the leak, it has also been stated that the main villain in the game will be Ultron who is infected by the Sigma virus (from Mega Man X). There have been reports that Mega Man will be relevant to the story, and seeing that Sigma is one of his major villains, it's possible that he will be on a mission to stop the infected Ultron before he does more damage to the universe. No official release date has been announced for Marvel vs. Capcom Infinite, but fans can expect the game to come out this year.