Zephyr is the Guardian of Hope, one of the four Guardian Lords, and the most powerful Guardian of them all; usually depicted as their leader. Zephyr takes on the form of a grand, golden-feathered dragon. Zephyr's power is usually sealed away at the start of the games because of the fact that hope has been drained out of the land and the general misery and troubles of living on the ruined-desert world of Filgaia.
Wild Arms/Wild Arms Alter Code F
It takes the strength of Rudy Roughknight's sense of hope to re-awaken him; Zephyr comments that of all the individuals who could revive him it happens to be a non-human and a non-Elw.