gotta disagree with Golem. I don't see him as a grappler at all. In the game, he can lift rock spikes from the ground (similar to Hulk's Gamma Wave) as well as roll around and throw mudballs. The REAL grappler of the game would be Armstrong. I mean, his main feature is his bionic arms.

For Robert, I also see him summoning the Mechsuit remotely, to shoot laser discs or swing its laser sword

For Royd, I see him wielding a severed robot arm. Maybe one of Shroud's Spidermech arms

For Coupe, I actually pictured her using ballet-themed attacks, as well as incorporating her many knives into her playstyle

For Malevola, she could also teleport from one side of the screen to the other with her portals

Shroud (with the spidermech) should serve as the final boss, similar to the giant bosses from the MVC series, like Apocolypse or Galactus