if your mouse is above the middle of the screen, Majin will become lit up. if your mouse is on the right side of the screen, Lord X will become lit up. if your mouse is on the right side and above the middle, both Majin and Lord X will become lit up. if your mouse is on the left and below the middle, both will become darkened. on mobile you should hopefully be able to change it by tapping the respective areas, which will also make the areas more easy to see if you click in one of the ones that light up the characters.
