The Legend of Zelda: Forgotten Gates

Rauru is probably the least fleshed-out of the Six Sages in the source material. All the other Sages you meet and interact with before they awaken as Sages, but Rauru is already a Sage when you meet him, and his role is to explain your second-act mission and send you off on it. Well, actually, there are hints that Kaepora Gaebora, the large owl who gives Link instruction dumps several times, is Rauru in a magical transformation, although it's not explicitly confirmed.

On Triforce MUCK-turned-Zelda RPG, I'm the player for Rauru, and I added some backstory for him. He came from a noble family and used the opportunity that afforded him to pursue the path of the scholar and priest. He eventually became a trusted advisor to the King of Hyrule, and was also one of Princess Zelda's tutors as she grew up. Rauru was aware of prophecies regarding the Hero of Time, and yes, helped to guide Link as Kaepora Gaebora...but he didn't know of his own role as the Sage of Light until Link claimed the Master Sword and was sealed within the Sacred Realm for his seven-year slumber.

In Forgotten Gates, Rauru is unsurprisingly anothersquishy wizard-type. Being a portly old man, he's slow and not very strong physically, but his magical ability rivals even Zelda's. His weapon of choice is daggers, mainly because they're something that could be hidden in those oversized sleeves of his. ;)