Prometheus was the Titan of daring thoughts and turns daring thoughts into daring deeds by making heroes out of ordinary units. This power works best on your armies, but will work on Citizens as well. If you expect your enemies to summon a lot of  <link="topic:myth units">myth units</link>, it is a good idea to use Valor before you go into battle.

To send the blessing of Prometheus on your units, left-click the Valor icon, and then left-click near a group of your units. This power works best on military units.