Metal Cap

The Metal Cap is an item worn by Mario, allowing him to become extremely durable and practically invincible. The result is enhanced strength, toughness, operation without air, and the inability to drown; given these powers, however, Metal Mario also becomes increasingly heavy, and more prone to sinking in water and quicksand. Metal Mario's appearance in the "Dimension" saga occurs during the Clash at the Valley of Bowser, as he fights Metal Sonic; he is shown to break through solid walls (of Bowser's castle) and withstand countless powerful attacks from his opponent, thanks to his increased durability—but in the end, Metal Sonic uses a chaos emerald to unleash an extremely powerful blast that finally rids Mario of his Metal Cap abilities, and even goes so far as to knock him unconscious for a long period of time.