The new gameplay video from Capcom doesn't reveal any new characters besides Ryu, Mega Man, Captain Marvel and Iron Man, but it does reveal that the Infinity Stones will play a prominent role and provide Power-Ups. Ryu and the Blue Bomber were absolutely working over Iron Man until a Carol Danvers arrives with the Time Stone.
Of course, if the Infinity Stones are featured, that can only mean that the mad Titan aka Thanos will be playing a role. The question know is whether he'll be a playable character or a Main Boss? And if he is the Main Boss, that also leads to which Capcom villain will he be teaming up with?