A palette swap of Blackheart. His physical basic attacks ignite the opponent when they connect, but this is just an aesthetic difference. He is Blackheart's father in the comics.
A gray version of Spider-Man that has limited armor, based on a metallic suit he wore in the comics as well as episodes later aired in the Marvel Studios animated series. He possess more resistance and sometimes no hit reaction to enemies attacks. He also has a slower walking speed and jumps slightly lower than before due to the heaviness of his armor. His damage from super combos is also reduced.
Although a distinctly different character than Captain America in the Marvel universe, he is just a palette swap in the game. He has, however, his own winning quotes, which are very aggressive in comparison to Captain America's.
A darkened version of Charlie with powerful super moves that have incredible start-up lag. A version of Charlie that suffered harsh experiments at Shadaloo's hands, and now serves them. At the time the game takes place however, he has broken free of their control.
A cyborg, amped-up version of Akuma created by Apocalypse. Also serves as the game's final boss. Called Mech-Gouki in Japan.
Secret Characters (Original)
Norimaro is a nerdish, cowardly schoolboy-type guy who is only available in the Japanese version of the game. He is armed with a camera and throws common school items, mini-Akuma dolls, and plushies as fireballs. He might even attempt to ask for his opponent's autograph mid-battle. But, despite this comic relief facade, he has some of the most powerful moves in the game. He is based on real-life Japanese comedian Noritake Kinashi.
There are several cameos of Rockman (Mega Man) in this game, in the mall stage, there's a cameo of a Rockman cut-out (perhaps someone in a Rockman suit), in relation to Capcom celebrating Rockman's "10th Anniversary" in 1997, they put a banner saying '10th Anniversary: Rockman' and in one of Norimaro's super combos, he does a cosplay of Rockman.
Charlie, Gambit, Rogue, and Rose appear in the background in the 'Showdown in the Park' stage.
Kei Chitose also appears at the beginning of matches when playing as Sakura.
Despite being a Japan-exclusive character, Norimaro CAN be selected by hacking the game. Many of his graphics, when viewed, have English counterparts, hinting he was planned to be released in English versions of the game at one point.
Omega Red's ending shows him having defeated/killed Ryu, with Ken deeply distressed and exalted questioning him shouting "how many lives have you ended?", to which only responds grinning "do you count the number of breaths you've taken?". This could be a reference to the manga series JoJo's Bizarre Adventure, specifically the scene where William Anthonio Zeppeli made a similar question toward vampire Dio Brando ("how many lives have you sucken away to heal those wounds?"), only to be answered cynically with "how many breads have you eaten in your life?".