Choose Spider as your character. Grapple (X) and then press X + up or X
+ down (after this move the opponent should be on the floor with their
legs facing you). When they are on the floor press X and you will do a
move which damages their leg health. When the move ends and the opponent
gets on to his feet repeat the process (grapple, then X + up or X + down
the X when the opponent is on the floor).