his weaknesses are radioactive rocks from his home planet that are called "kryptonite"; and magic. sometimes his enemies use it to hurt him. diffferent kryptoinites have different effects on him, blue kryptonite makes people able to control him using hypnosis, green weakens his powers and slowly kills him, black makes him evil, and red has many different effects on him (each piece of red kryptonite affects him differently). there is also gold, white, and jewel kryptonite. some of superman's enemies use magic to hurt him.