Now this is definitely up my Ally; I want to be part of this too!
Had some ideas for GyroMan & SpringMan.
GyroMan Concept:
His alt attack (origonally him being able to fly) causes him to spin his blades the wrong way, forcing him to fly straight backwards, building up speed untill he crashes painfully into a wall. Any opponent that might be behind the flying gyroman, will be instantly killed by his blades with a different death sound effect (unless its hardman, in which gyroman will instead explode, leaving hardman safe).
SpringMan Concept:
Whenever the player moves to any direction, he suddenly launches into the air (probably the hight of 1 and-a-half RushCoils), and leaves behind 3 springs whenever he lands onto the ground. If the player happens to hit his head on the ceiling, because of his insane jumping hight and distance, a nasty "cracking" sfx plays and tge player's screen is blinded by springman's 6-second comma, with a quick flash of white, then the screen is blocked with black. SpringMan is vulnerable to being killed while in a comma.
I'm somewhat worried that I went to detailed on the ideas, but I'm just throwing them out there. (Love the MagnetMan/ Turrent idea)