If you describe someone or something as protean, you mean that they have the ability to continually change their nature, appearance, or behaviour. He is a protean stylist who can move from blues to ballads and grand symphony. able to keep changing or to do many things (Proteus ancient Greek sea god who could change shape)
{s} easily changing form; having various forms; able to change body form (such as the amoeba); versatile, changeable