Ione Paua is the Saint Guardian. He takes on the physical form of a centaur and either wears armor or goes bare-chested on the human portion of his body; his number of hands change depending on the incarnation. Ione Paua only appeared in the original Wild Arms and it's remake, Wild Arms: Alter Code F.
Wild Arms/Wild Arms: Alter Code F
Ione Paua's Saint Rune can be found in Saint Centour after the town is attacked; it is received as part of the story in Alter Code F.