According to the Final Fantasy VII Ultimania Omega, earlier drafts of the game's scenario involved three characters known as the '3 Saints'. Not much is known about their original role in the story, other than they were kidnapped by Sephiroth, and that Red XIII knew more about them than the rest of your party. The only Saint mentioned by name was called Gandalf, who was captured by Hojo and "practically crippled" in a Shinra laboratory.
Contributed by EnoRed