Scarlet Witch. Marvel Hero Pawn.
Magneto. Marvel Villains Bishop.
Scorpion. Marvel Villain Rook or Knight, depending on the success of possible "Rhino" and "Juggernaut" figures to build and use as Rooks.
Mr. Fantastic. Marvel Hero King.
The Hulk. Marvel Hero Rook.
Hawkeye. Marvel Hero Pawn.
Kang. Marvel Villain Knight, maybe but probably not.
Kingpin. Marvel Villain King.
Iron Man. Marvel Hero Knight.