Based on the excerpts provided, both Prospero and Medea have the power to control wind and influence natural elements. Specifically, Medea invokes the powers of night, stars, and various natural elements to perform magic, while Prospero, in "The Tempest," is known for his control over the elements, including the wind and sea.
However, regarding the specific mention of restoring youth, Medea explicitly asks for the "juices" to renew old age and return to the bloom of life, indicating she possesses the power to restore youth.
Therefore, the correct response based on the passages is: They can restore youth.