<P> Citadel is a superhero with indestructible skin that can deflect magnetic fields . Citadel first appeared in "Sm'oliver's Travels", where he had stomach pains . Due to his indestructible skin, surgery could not be performed on him, so Oliver was shrunken and sent inside his body to remove the source of the pain . </P> <P> He reappears in "The Friend of My Friend Is My Enemy" where Oliver used an advanced stethoscope to hear his heartbeat . </P> <P> The Great Defender (Dwight Howard) is from another planet, like Skylar . His suit is indestructible and his powers consist of ice ball projection, superhuman strength, and spinning things at high speed on his fingertips like a basketball . Despite being six feet and 11 inches, he is the shortest person on his planet . He appeared in "Pranks for Nothing", where Kaz played a prank on him by super-gluing a coin to his hand . He later tricked Kaz and Oliver into thinking he spun the Earth on his finger and pretended that his powers weren't working . He then had Solar Flare heat up the hospital to make them think the Earth was hurling towards the sun and had Horace make them think they had to sacrifice themselves to save the Earth . </P> <P> He was mentioned by Alan in "Alan's Reign of Terror" where Alan had him slow down the rotation of a planet so that his uncle's appointment there would be longer . </P>

Who plays the great defender of mighty med